Stockholders' Equity and EPS - Reclassifications out of AOCI (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Related tax expense	$ (63,066)	$ (61,296)	[1]
Net income available to common stockholders	88,516	90,950	[1],[2]
Reclassification out of Accumulated Other Comprehensive Income | Gains on investment securities, net
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Reclassification adjustment for (gains) losses included in net income	(2,596)	(60)
Related tax expense	1,048	24
Net income available to common stockholders	$ (1,548)	$ (36)

[1] 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.

[2] Results for the quarter ended March 31, 2014 were restated to reflect the retrospective application of adopting new accounting guidance in 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 of the Notes to Consolidated Financial Statements for additional information.