Document and Entity Information Document Type Document Annual Report Document Transition Report Document Period End Date Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Title of 12(b) Security Trading Symbol Security Exchange Name Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company ICFR Auditor Attestation Flag Entity Shell Company Entity Common Stock, Shares Outstanding Entity Public Float Entity Central Index Key Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Amendment Flag Document Financial Statement Error Correction [Flag] Documents Incorporated by Reference [Text Block] Auditor Name Auditor Firm ID Auditor Location CONSOLIDATED INCOME STATEMENT Revenues Revenue Revenues Cost of Revenue Cost of services Selling, General and Administrative Expense Selling, general and administrative expenses The amount of expenses related to workforce rebalancing charges. Workforce Rebalancing Costs Workforce rebalancing charges Business Combination, Acquisition Related Costs Transaction-related (costs) benefits Transaction-related costs (benefits) Interest Expense Interest expense Interest expense The aggregate amount of (income) expense , not previously categorized, including interest income, gains and losses on certain derivative instruments, gains and losses from securities and other investments, gains and losses from certain real estate transactions, foreign currency transaction gains and losses, gains and losses from the sale of businesses and amounts related to accretion of asset retirement obligations. Other Income and Expense Other expense The aggregate amount of both recurring costs and income associated with normal operations (except for the portion of these expenses which can be clearly related to production and included in cost of sales, services or financing) and expense (income) from ancillary business-related activities. Includes selling, general and administrative expense, research, development and engineering expense, intellectual property and custom development income and interest and debt related expenses (except those related to the financing activities of the entity). Expense and Other Income Total costs and expenses Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income (loss) before income taxes Income Tax Expense (Benefit) Provision for income taxes Total provision for income taxes Profit Loss Net income (loss) Net income (loss) Net income (loss) on which basic and diluted earnings per share is calculated EARNINGS PER SHARE Earnings Per Share, Basic Basic earnings (loss) per share Basic earnings (loss) per share (in dollars per share) Earnings Per Share, Diluted Diluted earnings (loss) per share Diluted earnings (loss) per share (in dollars per share) Weighted Average Number of Shares Outstanding, Basic Number of shares on which basic earnings (loss) per share is calculated Weighted-average basic shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Number of shares on which diluted earnings (loss) per share is calculated Weighted-average diluted shares outstanding (in shares) Statement [Table] Related Party [Axis] Related Party [Domain] Related Party [Member] Statement [Line Items] Equity Activity CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) Other Comprehensive Income (Loss), before Tax [Abstract] Other comprehensive income (loss), before tax: Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax [Abstract] Foreign currency translation adjustments: Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax Foreign currency translation adjustments Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, before Tax Unrealized gains (losses) on net investment hedges Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent Total foreign currency translation adjustments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax, Parent [Abstract] Unrealized gains (losses) on cash flow hedges: Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Unrealized gains (losses) arising during the period Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Reclassification of (gains) losses to net income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax, Parent Total unrealized gains (losses) on cash flow hedges Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract] Retirement-related benefit plans: Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax Prior service costs (credits) Current period prior service costs (credits) Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax Current period loss (gain) Net gains (losses) arising during the period Other Comprehensive Income (Loss), Finalization of Pension and Other Postretirement Benefit Plan Valuation, before Tax Curtailments and settlements Curtailments and settlements Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax Amortization of prior service (credits) costs Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax Amortization of net (gains) losses Amortization of net loss included in net periodic benefit cost Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, Portion Attributable to Parent Total retirement-related benefit plans Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Other comprehensive income (loss), before tax Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Income tax (expense) benefit related to items of other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Other comprehensive income (loss), net of tax Comprehensive Income (Loss), Net of Tax, Attributable to Parent Total comprehensive income (loss) CONSOLIDATED BALANCE SHEET Assets [Abstract] Assets: Assets, Current [Abstract] Current assets: Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Restricted Cash Restricted cash Accounts Receivable, Net, Current Accounts receivable (net of allowances for credit losses of $13 at March 31, 2025 and $22 at March 31, 2024) Accounts receivable (net of allowances for credit losses of $13 at March 31, 2025 and $22 at March 31, 2024) * Capitalized Contract Cost, Net, Current Deferred costs (current portion) Deferred costs, current Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets Assets, Current Total current assets Property, Plant and Equipment, Net Property, plant and equipment - net Property and equipment, net Operating Lease, Right-of-Use Asset Operating right-of-use assets, net Capitalized Contract Cost, Net, Noncurrent Deferred costs (noncurrent portion) Deferred costs, noncurrent Deferred Income Tax Assets, Net Deferred taxes Goodwill Ending Balance Beginning Balance Goodwill Finite-Lived Intangible Assets, Net Intangible assets, net Net Carrying Amount Defined Benefit Plan, Assets for Plan Benefits, Noncurrent Noncurrent assets - pension assets Pension assets Other Assets Other noncurrent assets Assets Total assets Liabilities and Equity [Abstract] Liabilities and equity Liabilities [Abstract] Liabilities: Liabilities, Current [Abstract] Current liabilities: Accounts Payable, Current Accounts payable Sales and Excise Tax Payable, Current Value-added tax and income tax liabilities Short-term Debt Current portion of long-term debt Employee-related Liabilities, Current Current liabilities - accrued compensation and benefits Accrued compensation and benefits Deferred Revenue, Current Deferred income (current portion) Deferred income (current) Operating Lease, Liability, Current Operating lease liabilities (current portion) Accrued Liabilities, Current Accrued contract costs Current portion of the amount of expenses incurred but not yet paid nor invoiced, and liabilities classified as other. Accrued Liabilities and Other Liabilities, Current Other accrued expenses and liabilities Other accrued expenses and liabilities Liabilities, Current Total current liabilities Long-term Debt and Lease Obligation Long-term debt Total Noncurrent liability for retirement and nonpension postretirement benefit Noncurrent liabilities - retirement and nonpension postretirement benefit obligations Retirement and nonpension postretirement benefit obligations Deferred Revenue, Noncurrent Deferred income (noncurrent portion) Deferred income (noncurrent) Operating Lease, Liability, Noncurrent Operating lease liabilities (noncurrent portion) Other Liabilities, Noncurrent Other noncurrent liabilities Other non-current liabilities Total liabilities Total liabilities Commitments and contingencies Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Stockholders' equity Common Stocks, Including Additional Paid in Capital Common stock, par value $0.01 per share, and additional paid-in capital (shares authorized: 1,000.0; shares issued: March 31, 2025 - 238.2, March 31, 2024 - 233.7) Retained Earnings (Accumulated Deficit) Accumulated deficit Treasury Stock, Value Treasury stock, at cost (shares: March 31, 2025 - 7.5, March 31, 2024 - 3.3) Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income (loss) Stockholders' Equity Attributable to Parent Total stockholders' equity before non-controlling interests Stockholders' Equity Attributable to Noncontrolling Interest Non-controlling interests Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance at the end of the period Balance at the beginning of the period Total equity Liabilities and Equity Total liabilities and equity Allowance for Doubtful Accounts Receivable, Current Notes and accounts receivable - trade, allowances Accounts receivable, allowances Common Stock, Par or Stated Value Per Share Common Stock, Par value (in dollars per share) Common Stock, Shares Authorized Common Stock, Shares authorized (in shares) Common Stock, Shares, Issued Common Stock, Shares issued (in shares) Treasury Stock, Shares Treasury Stock (in shares) CONSOLIDATED STATEMENT OF CASH FLOWS Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income (loss) to cash provided by operating activities: Depreciation Depreciation of property, equipment and capitalized software Depreciation of property, equipment and capitalized software Operating Lease, Right-of-Use Asset, Amortization Expense Depreciation of right-of-use assets Amount of amortization of transition costs and prepaid software. Amortization of Transition Costs and Prepaid Software Amortization of transition costs and prepaid software Capitalized Contract Cost, Amortization Amortization of deferred costs Amortization of capitalized contract costs Amortization of Intangible Assets Amortization of acquisition-related intangible assets Share-based Compensation Stock-based compensation expense Stock-based compensation Deferred Income Tax Expense (Benefit) Deferred taxes Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee, and amount of income (expense) included in net income that results in no cash inflow (outflow), classified as other. Gain (Loss) on Disposition of Assets and Other Net (gain) loss on asset sales and other Increase (Decrease) in Operating Capital [Abstract] Change in operating assets and liabilities: Increase (Decrease) in Deferred Charges Deferred costs (excluding amortization) Amount of increase decrease in right of use assets and liabilities. Increase (Decrease) in Right Of Use Assets And Liabilities Right-of-use assets and liabilities (excluding depreciation) Amount of increase (decrease) in workforce rebalancing. Increase Decrease In Workforce Rebalancing Workforce rebalancing liabilities Increase (Decrease) in Accounts Receivable Receivables Increase (Decrease) in Accounts Payable Accounts payable Amount of increase (decrease) in taxes including items settled with parent. Increase Decrease In Taxes Including Items Settled With Parent Taxes Increase (Decrease) in Other Operating Assets and Liabilities, Net Other assets and other liabilities Net Cash Provided by (Used in) Operating Activities Net cash provided by operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities: Payments to Acquire Property, Plant, and Equipment Capital expenditures Payment for purchase of hardware from IBM Proceeds from Sale of Property, Plant, and Equipment Proceeds from disposition of property and equipment Payments for (Proceeds from) Businesses and Interest in Affiliates Acquisitions and divestitures, net of cash acquired Payments for (Proceeds from) Other Investing Activities Other investing activities, net Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities: Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities Debt repayments Proceeds from Issuance of Long-term Debt and Capital Securities, Net Proceeds from issuance of debt, net of debt issuance costs Payments for Repurchase of Common Stock Common stock repurchases Payments Related to Tax Withholding for Share-based Compensation Common stock repurchases for tax withholdings Proceeds from (Payments for) Other Financing Activities Other financing activities, net Net Cash Provided by (Used in) Financing Activities Net cash used in financing activities Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Effect of exchange rate changes on cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Net change in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents and restricted cash at end of period Cash, cash equivalents and restricted cash at beginning of period Supplemental Cash Flow Information [Abstract] Supplemental data Income Taxes Paid, Net Income taxes paid, net of refunds received Interest Paid, Excluding Capitalized Interest, Operating Activities Interest paid on debt CONSOLIDATED STATEMENT OF EQUITY Equity Components [Axis] Equity Component [Domain] Common Stock Including Additional Paid in Capital [Member] Common Stock and Additional Paid-In Capital AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) Treasury Stock, Common [Member] Treasury Stock Retained Earnings [Member] Accumulated Deficit Noncontrolling Interest [Member] Non-Controlling Interests Increase (Decrease) in Stockholders' Equity [Roll Forward] Equity Changes in AOCI for retirement-related benefits Shares, Outstanding Balance at the end of the period (in shares) Balance at the beginning of the period (in shares) Other Comprehensive Income (Loss), Net of Tax Other comprehensive income (loss) Other comprehensive income (loss) Other comprehensive income (loss), net of tax Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture Activity related to employee stock plans Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Activity related to employee stock plans (in shares) Stock Repurchased During Period, Value Purchases of treasury stock Purchases of treasury stock Stock Repurchased During Period, Shares Purchases of treasury stock (in shares) Purchases of treasury stock (in shares) Noncontrolling Interest, Period Increase (Decrease) Changes in non-controlling interests SIGNIFICANT ACCOUNTING POLICIES Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] SIGNIFICANT ACCOUNTING POLICIES ACCOUNTING PRONOUNCEMENTS Accounting Changes and Error Corrections [Text Block] ACCOUNTING PRONOUNCEMENTS REVENUE RECOGNITION Revenue from Contract with Customer [Text Block] REVENUE RECOGNITION SEGMENTS