Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 4,089	$ 4,288	$ 12,257	$ 13,344
United States
Disaggregation of Revenue [Line Items]
Revenues	1,168	1,290	3,570	4,665
United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	578	607	1,749	1,759
Other Europe
Disaggregation of Revenue [Line Items]
Revenues	1,319	1,335	3,878	3,784
Australia
Disaggregation of Revenue [Line Items]
Revenues	376	377	1,172	1,128
Other International
Disaggregation of Revenue [Line Items]
Revenues	$ 648	$ 679	$ 1,888	$ 2,008