Commitments and Contingencies Fiscal Year Maturity Schedule (Details) $ in Millions	Dec. 31, 2016 USD ($)
Loans and Mortgage-Related Securities [Abstract]
2017	$ 67,100
2018	0
2019	0
2020	0
2021	0
Thereafter	0
Total	67,100
Operating Leases [Abstract]
2017	47
2018	32
2019	44
2020	50
2021	49
Thereafter	665
Total	887
Other [Abstract]
2017	88
2018	36
2019	18
2020	8
2021	3
Thereafter	0
Total	153
Mortgage commitment derivatives [Member]
Loans and Mortgage-Related Securities [Abstract]
Total	$ 66,700