Stockholders' Equity (Deficit) - Schedule of Other Comprehensive Income (Loss), Net of Tax (Details) € in Millions, £ in Millions, $ in Millions	3 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 EUR (€)	Mar. 31, 2021 EUR (€)	Jun. 30, 2020 EUR (€)	Sep. 30, 2019 GBP (£)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	$ 12	$ 27
Reclassified to income statement, net of income tax expense	14	2
Other comprehensive income (loss), net of tax	26	29
Foreign currency translation adjustments, tax	0	0
Reclassified to income statement, tax	0	0
Unrealized gains (loss) on cash flow hedges arising during period, tax	0	0
Net actuarial loss and prior service cost arising during the period, tax	0	0
Amortization of actuarial (gain) loss and prior service costs, tax	0	0
Foreign currency translation adjustments and other, tax	0	0
Net actuarial gain (losses) attributable to redeemable noncontrolling interest	0	3
Foreign Currency Translation Adjustments, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	34	96
Reclassified to income statement, net of income tax expense	17	0
Other comprehensive income (loss), net of tax	51	96
Translation gain (loss) attributable to redeemable noncontrolling interest	9	58
Unrealized Losses on Net Investment Hedges, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	(27)	(63)
Reclassified to income statement, net of income tax expense	0	0
Other comprehensive income (loss), net of tax	(27)	(63)
Unrealized gains (losses) on net investment hedges arising during period, tax	6	22
Reclassified to income statement, tax	0	0
Gain (loss) from net investment hedges recorded within other comprehensive income	(6)
Unrealized Gains (Losses) on Cash Flow Hedges, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	0	(5)
Reclassified to income statement, net of income tax expense	0	0
Other comprehensive income (loss), net of tax	0	(5)
Reclassified to income statement, tax	0	0
Net actuarial loss and prior servicecost arising during the period, net of income tax benefit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	5	0
Amortization of actuarial loss, prior service cost and transition obligation, net of income tax expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	(1)	2
Foreign currency translation adjustments and other, net of income tax expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications	0	(1)
Changes in retirement-related benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassified to income statement, net of income tax expense	(2)	0
Other comprehensive income (loss), net of tax	2	1
Reclassified to income statement, tax	1	0
Euro Denominated Notes | Term Loan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Long-term debt outstanding | €					€ 1,700
British Pound Sterling Denominated Notes | Term Loan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Long-term debt outstanding | £						£ 450
Net Investment Hedging | Euro Denominated Notes | Term Loan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Long-term debt outstanding | €			€ 1,700	€ 1,700
Derivatives designated for hedge accounting
Accumulated Other Comprehensive Income (Loss) [Line Items]
Gain (loss) from net investment hedges recorded within other comprehensive income	(22)	(34)
Derivatives designated for hedge accounting | Net Investment Hedging
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivatives used in net investment hedge, gains (losses) gross	$ (5)	$ (51)