Off-Balance Sheet Lending-Related Financial Instruments, Guarantees and Other Commitments - Loan Sales- and Securitization-Related Indemnifications (Details) - Loans sold with recourse - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Loans sold with recourse
Unpaid principal balance of loans sold with recourse	$ 2,730	$ 4,274
Carrying value of related liability for recourse obligations	$ 64	$ 82