Fair Value - Fair Value Measurements on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2020	Mar. 31, 2019
Recurring
Assets:
Money market funds and money market deposit accounts	$ 156	$ 6
Time deposits	595	194
Other debt securities	51	53
Deferred purchase price receivable	103	574
Total assets	905	827
Liabilities:
Contingent consideration	46	41
Total liabilities	46	41
Recurring | Level 1
Assets:
Money market funds and money market deposit accounts	156	6
Time deposits	595	194
Other debt securities	0	0
Deferred purchase price receivable	0	0
Total assets	751	200
Liabilities:
Contingent consideration	0	0
Total liabilities	0	0
Recurring | Level 2
Assets:
Money market funds and money market deposit accounts	0	0
Time deposits	0	0
Other debt securities	48	49
Deferred purchase price receivable	0	0
Total assets	48	49
Liabilities:
Contingent consideration	0	0
Total liabilities	0	0
Recurring | Level 3
Assets:
Money market funds and money market deposit accounts	0	0
Time deposits	0	0
Other debt securities	3	4
Deferred purchase price receivable	103	574
Total assets	106	578
Liabilities:
Contingent consideration	46	41
Total liabilities	46	41
Other Debt Securities
Liabilities:
Available-for-sale, cost basis	37	38
Available-for-sale, unrealized gain	$ 11	$ 11