Variable Interest Entities - Additional Information (Details) $ in Thousands	Dec. 31, 2015 USD ($) entity	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Variable Interest Entity [Line Items]
Number of deconsolidated entities | entity	16
Total assets	$ (44,686,703)	$ (39,337,869)
Total equity	$ (3,333,231)	(4,051,734)	$ (3,074,693)
Number of consolidated entities | entity	5
Maximum Exposure to Loss in Unconsolidated VIEs	$ 364,450
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Total assets	(364,450)
Accrued expenses and other liabilities	90,978
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Total assets	(216,019)
Accrued expenses and other liabilities	0
Maximum Exposure to Loss in Unconsolidated VIEs	215,600
Cumulative-Effect Adjustment, Deconsolidation of Variable Interest Entity
Variable Interest Entity [Line Items]
Total assets	1,100,000
Total equity	1,200,000
Low income housing tax credit funds
Variable Interest Entity [Line Items]
Non-marketable and other securities	$ 154,356	$ 121,155