Variable Interest Entities - Carrying Amounts and Classification of Significant Variable Interests (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	[1],[2]	Dec. 31, 2014	[1],[2]
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 1,868,512	$ 1,503,257	$ 1,263,846		$ 1,811,014
Non-marketable and other securities	668,497	674,946
Accrued interest receivable and other assets	548,108	709,707
Total assets	43,573,902	44,686,703
Other liabilities	506,571	639,094
Total liabilities	40,062,862	41,353,472
Maximum Exposure to Loss in Unconsolidated VIEs	362,470	364,450
Consolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents	10,855	11,811
Non-marketable and other securities	196,789	203,714
Accrued interest receivable and other assets	614	494
Total assets	208,258	216,019
Other liabilities	563	433
Accrued expenses and other liabilities	0	0
Total liabilities	563	433
Maximum Exposure to Loss in Unconsolidated VIEs	207,700
Unconsolidated
Variable Interest Entity [Line Items]
Non-marketable and other securities	362,470	364,450
Total assets	362,470	364,450
Accrued expenses and other liabilities	87,754	90,978
Total liabilities	87,754	90,978
Low Income Housing Tax Credit Funds | Consolidated
Variable Interest Entity [Line Items]
Non-marketable and other securities	$ 157,700	$ 154,400

[1] Amounts for the three months ended March 31, 2015, have been revised to reflect the retrospective application of new accounting guidance adopted in the second quarter of 2015 related to our consolidated variable interest entities (ASU 2015-02).

[2] Cash and cash equivalents at March 31, 2015 and December 31, 2014 included $9.3 million and $15.0 million, respectively, recognized in assets held-for-sale in conjunction with the SVBIF sale transaction.