Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Information
External revenue	$ 4,434.0	$ 4,696.0	$ 13,657.0	$ 13,941.0
Related party revenue	144.0	161.0	445.0	483.0
Total revenue	4,579.0	4,856.0	14,102.0	14,425.0
Pre-tax income (loss)	(469.0)	(170.0)	(1,191.0)	(1,050.0)
Americas
Segment Information
External revenue	1,641.0	1,745.0	5,056.0	5,269.0
Related party revenue	97.0	96.0	278.0	284.0
Total revenue	1,737.0	1,841.0	5,334.0	5,553.0
Pre-tax income (loss)	(89.0)	(13.0)	(211.0)	(230.0)
EMEA
Segment Information
External revenue	1,717.0	1,807.0	5,293.0	5,301.0
Related party revenue	23.0	29.0	78.0	92.0
Total revenue	1,741.0	1,837.0	5,370.0	5,394.0
Pre-tax income (loss)	(381.0)	(280.0)	(1,126.0)	(1,101.0)
Japan
Segment Information
External revenue	719.0	752.0	2,194.0	2,204.0
Related party revenue	10.0	17.0	42.0	53.0
Total revenue	729.0	769.0	2,236.0	2,257.0
Pre-tax income (loss)	23.0	56.0	78.0	131.0
Asia Pacific
Segment Information
External revenue	358.0	392.0	1,114.0	1,168.0
Related party revenue	14.0	18.0	47.0	54.0
Total revenue	372.0	410.0	1,161.0	1,222.0
Pre-tax income (loss)	$ (23.0)	$ 66.0	$ 68.0	$ 149.0