Earnings Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net income	$ 18,808	$ 16,924	$ 72,657	$ 46,441
Preferred stock dividends	(2,194)	(2,194)	(6,582)	(5,021)
Net income available to common shareholders	16,614	14,730	66,075	41,420
Income allocated to participating securities	(187)	(195)	(742)	(508)
Net income allocated to common shareholders	$ 16,427	$ 14,535	$ 65,333	$ 40,912
Basic weighted average common shares outstanding	98,453,265	97,199,329	98,279,671	96,967,052
Dilutive effect of stock options and restricted stock units	0	0	0	0
Diluted weighted average common shares outstanding	98,453,265	97,199,329	98,279,671	96,967,052
Basic EPS	$ 0.17	$ 0.15	$ 0.66	$ 0.42
Diluted EPS	$ 0.17	$ 0.15	$ 0.66	$ 0.42
Options
Antidilutive securities excluded from computation of earnings per share
Stock options excluded from computation of earnings per share (in shares)	988,050	1,871,935	1,016,451	2,215,820
Restricted stock units (RSUs)
Antidilutive securities excluded from computation of earnings per share
Restricted stock units excluded from the computation of earning per share (in shares)	788,874	415,900	751,149	379,602