Offsetting Arrangements - Repo, Sec Lending Transactions Maturity By Category (Details) $ in Millions	Jun. 30, 2015 USD ($)
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	$ 42,006
Securities Loaned, Gross	7,217
Securities Sold and Securities Loaned Under Agreements to Repurchase, Gross	49,223
Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	41,684
Securities Loaned, Gross	6,163
Securities Sold and Securities Loaned Under Agreements to Repurchase, Gross	47,847
Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	322
Securities Loaned, Gross	0
Securities Sold and Securities Loaned Under Agreements to Repurchase, Gross	322
30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	0
Securities Loaned, Gross	1,054
Securities Sold and Securities Loaned Under Agreements to Repurchase, Gross	1,054
US Treasury and agency securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	41,698
US Treasury and agency securities | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	41,684
US Treasury and agency securities | Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	14
US Treasury and agency securities | 30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	0
Corporate securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Gross	1
Corporate securities | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Gross	1
Corporate securities | Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Gross	0
Corporate securities | 30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Gross	0
U.S. equity securities
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Gross	7,216
U.S. equity securities | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Gross	6,162
U.S. equity securities | Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Gross	0
U.S. equity securities | 30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Gross	1,054
Non-US sovereign debt
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	308
Non-US sovereign debt | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	0
Non-US sovereign debt | Up to 30 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	308
Non-US sovereign debt | 30 – 90 days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase, Gross	$ 0