Securitizations and Other Variable Interest Entities - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Variable Interest Entity [Line Items]
Consolidated total assets	$ 2,186,609	$ 2,144,316	$ 2,149,034
Accounting Standards Update 2015-02 | Unconsolidated VIEs
Variable Interest Entity [Line Items]
Maximum loss exposure	4,600
Consolidated total assets	$ 12,900