Variable Interest Entities - Carrying Amounts and Classification of Significant Variable Interests (Details)(Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	[1]	Dec. 31, 2013
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 2,545,750	$ 1,503,257	$ 1,811,014		$ 1,538,779
Non-marketable and other securities	622,552	674,946
Accrued interest receivable and other assets	672,688	709,707
Total assets	44,683,660	44,686,703
Other liabilities	618,383	639,094
Total liabilities	40,906,623	41,353,472
Maximum Exposure to Loss in Unconsolidated VIEs	314,810	364,450
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Cash and cash equivalents	11,469	11,811
Non-marketable and other securities	196,140	203,714
Accrued interest receivable and other assets	294	494
Total assets	207,903	216,019
Accrued expenses and other liabilities	517	433
Total liabilities	517	433
Maximum Exposure to Loss in Unconsolidated VIEs	207,400
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Cash and cash equivalents	0	0
Non-marketable and other securities	314,810	364,450
Accrued interest receivable and other assets	0	0
Total assets	314,810	364,450
Accrued expenses and other liabilities	58,095	90,978
Total liabilities	$ 58,095	$ 90,978

[1] Cash and cash equivalents at December 31, 2014 included $15.0 million recognized in assets held-for-sale in conjunction with the SVBIF sale transaction. On April 13, 2015 we received net proceeds of $39.3 million consisting of the sales price of $48.6 million less $9.3 million of cash and cash equivalents held by SVBIF that were sold.