Variable Interest Entities - Carrying Amounts and Classification of Significant Variable Interests (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	[1]	Dec. 31, 2013	[1],[2]
Variable Interest Entity [Line Items]
Cash and cash equivalents		$ 1,674,145	$ 1,796,062	$ 1,872,537		$ 1,538,779
Non-marketable and other securities	[3]	650,555	1,728,140
Accrued interest receivable and other assets	[3]	580,370	553,208
Total assets		41,730,982	39,337,869
Other liabilities		566,370	483,493
Total liabilities		38,416,754	$ 35,286,135
Maximum Exposure to Loss in Unconsolidated VIEs		341,065
Consolidated
Variable Interest Entity [Line Items]
Cash and cash equivalents		18,769
Non-marketable and other securities		204,555
Accrued interest receivable and other assets		375
Total assets		223,699
Other liabilities		421
Accrued expenses and other liabilities		0
Total liabilities		421
Maximum Exposure to Loss in Unconsolidated VIEs		223,300
Unconsolidated
Variable Interest Entity [Line Items]
Non-marketable and other securities		341,065
Total assets		341,065
Accrued expenses and other liabilities		65,305
Total liabilities		65,305
Maximum Exposure to Loss in Unconsolidated VIEs		341,100
Low Income Housing Tax Credit Funds | Consolidated
Variable Interest Entity [Line Items]
Non-marketable and other securities		$ 125,500

[1] Cash flows for the nine months ended September 30, 2015 were revised to reflect the adoption of ASU 2015-02 as of January 1, 2015 and cash flows for the nine months ended September 30, 2014 were revised to reflect the retrospective application of our adoption of ASU 2014-01.

[2] 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.

[3] Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1— "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.