Commitments, Contingencies and Guarantees (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($)
Commitments to extend credit
Commitment, Contingencies and Guarantees disclosures
Commitments	$ 33,233
Issued standby and commercial letters of credit
Commitment, Contingencies and Guarantees disclosures
Commitments	$ 5,897
Maximum term	1 year
Carrying value	$ 4
Other commitments
Commitment, Contingencies and Guarantees disclosures
Commitments	116
Oil and Gas [Member] | Commitments to extend credit
Commitment, Contingencies and Guarantees disclosures
Commitments	$ 2,952