TRANSITION PERIOD - Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2021
Cash flows from operating activities:
Net income (loss)	$ (229)	$ (494)	$ (340)	$ (1,374)	$ (2,304)
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation of property, equipment and capitalized software	246	339	834	900	1,300
Depreciation of right-of-use assets	103	99	319	428	327
Amortization of transition costs and prepaid software	319	323	1,256	1,199	1,278
Amortization of capitalized contract costs	136	160	531	472	563
Amortization of acquisition-related intangible assets	7	7	30	46	37
Stock-based compensation	31	16	95	113	71
Deferred taxes	(10)	17	(13)	285	(401)
Net (gain) loss on asset sales and other	12	(1)	43	6	11
Change in operating assets and liabilities:
Deferred costs (excluding amortization)	(672)	(548)	(1,569)	(1,592)	(1,618)
Right-of-use assets and liabilities (excluding depreciation)	(117)	(118)	(335)	(361)	(374)
Workforce rebalancing liabilities	(73)	(138)	(38)	41	(341)
Receivables	(31)	(138)	11	664	(1,076)
Accounts payable	384	(99)	(305)	282	125
Taxes (including items settled with former Parent in 2021 period)	(66)	74	(2)	90	994
Other assets and other liabilities	151	172	(63)	(415)	822
Net cash provided by (used in) operating activities	189	(328)	454	781	(119)
Cash flows from investing activities:
Payments for property and equipment	(180)	(180)	(651)	(865)	(752)
Proceeds from disposition of property and equipment	9	93	138	23	194
Other investing activities, net	(53)	(13)	(40)	7	(14)
Net cash used in investing activities	(225)	(100)	(553)	(835)	(572)
Cash flows from financing activities:
Debt repayments	(28)	(17)	(644)	(118)	(91)
Net transfers from Parent		460			(30)
Common stock repurchases for tax withholdings	(3)		(22)	(19)	(1)
Other financing activities, net	(12)		2	(4)
Net cash provided by (used in) financing activities	(43)	443	(170)	(141)	2,915
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(7)	(3)	(37)	(100)	(22)
Net change in cash, cash equivalents and restricted cash	(86)	13	(306)	(294)	2,203
Cash, cash equivalents and restricted cash at beginning of period	2,240	38	1,860	2,154	38
Cash, cash equivalents and restricted cash at end of period	2,154	$ 50	1,554	1,860	2,240
Supplemental data
Income taxes paid, net of refunds received	47		191	167	12
Interest paid on debt	$ 3		$ 118	$ 98	$ 2