Segment Information - Total Assets (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Assets
Total assets:	$ 8,825	$ 8,882	$ 9,504
Reportable Segment Totals
Assets
Total assets:	8,291	8,434	8,591
Americas
Assets
Total assets:	4,755	4,927	4,693
Europe
Assets
Total assets:	3,536	3,507	3,290
Asia Pacific
Assets
Total assets:			608
Other
Assets
Total assets:	$ 534	$ 448	$ 913