Offsetting Arrangements - Assets With Enforceable Netting Arrangements (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Offsetting [Abstract]
Derivatives, net amount of assets presented in statement of condition	$ 3,503	$ 4,777
Derivatives, counterparty netting	0	0
Derivatives, cash and securities received	(159)	(405)
Derivatives, net amount	3,344	4,372
Resale agreements and securities borrowing, resale agreements and securities borrowing, net amount of assets presented in statement of condition	26,153	23,525
Resale agreements and securities borrowing, counterparty netting	(120)	(63)
Resale agreements and securities borrowing, cash and securities received	(25,783)	(22,812)
Resale agreements and securities borrowing, net amount	250	650
Total, net amounts of assets presented in statement of condition	29,656	28,302
Total, counterparty netting	(120)	(63)
Total, cash and securities received	(25,942)	(23,217)
Total, net amount	$ 3,594	$ 5,022