Offsetting Arrangements - Liabilities With Enforceable Netting Arrangements (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Offsetting [Abstract]
Derivative, net amount of liabilities presented in statement of condition	$ 7,703	$ 4,132
Derivative, counterparty netting	0	0
Derivative, collateral provided	(136)	(64)
Derivative, net amount	7,567	4,068
Repurchase agreements and securities lending, net amount of liabilities presented in statement of condition	8,983	7,769
Repurchase agreements and securities lending, counterparty netting	(108)	(63)
Repurchase agreements and securities lending, collateral provided	(6,622)	(5,287)
Repurchase agreements and securities lending, net amount	2,253	2,419
Total, net amount of liabilities presented in statement of condition	16,686	11,901
Total, counterparty netting	(108)	(63)
Total, collateral provided	(6,758)	(5,351)
Total, net amount	$ 9,820	$ 6,487