Commitments, Guarantees and Contingent Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Guarantees and Contingent Liabilities
Total rent expense for all leases	$ 179	$ 187	$ 192
Capital leases, future minimum lease payments
2016	5
2017	0
2018	0
2019	0
2020	0
Thereafter	0
Total	5
Present value of minimum capital lease payments	5
Operating leases, future minimum lease payments
2016	132
2017	105
2018	87
2019	73
2020	58
Thereafter	175
Total	$ 630