Contracts Accounted for as Credit Derivatives - Credit Derivatives Subordination and Ratings (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	$ 12,856	$ 16,997
Pooled corporate obligations [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	6,860	10,425
Pooled corporate obligations [Member] | CLO/collateralized bond obligations [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	1,461	2,022
Pooled corporate obligations [Member] | Synthetic investment grade pooled corporate [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	4,400	7,224
Pooled corporate obligations [Member] | TruPS CDOs [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	999	1,179
RMBS [Member] | United States [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	1,080	1,142
Pooled Infrastructure Transactions [Member] | United States [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	1,363	1,513
Infrastructure Finance [Member] | United States [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	832	1,021
Other [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	$ 2,721	$ 2,896