Commitments, Guarantees and Contingencies Aggregate Minimum Rentals (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
2019		$ 61
2020		53
2021		40
2022		33
2023		26
Thereafter		65
Total	[1]	278
Operating lease expense		$ 83	$ 84	$ 59

[1] Minimum payments have not been reduced by minimum sublease rentals due in the future under noncancelable subleases.