Segment Information - Total Assets (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Assets
Total assets:	$ 8,624	$ 9,610	$ 9,548
Reportable Segment Totals
Assets
Total assets:	7,970	9,085	8,989
Americas
Assets
Total assets:	4,663	5,264	5,241
Europe
Assets
Total assets:	3,307	3,127	3,053
Asia Pacific
Assets
Total assets:		694	695
Other
Assets
Total assets:	$ 654	$ 525	$ 559