Earnings Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Net income	$ 95,916	$ 66,593	$ 53,091
Preferred stock dividends	(8,775)	(7,214)	0
Net income available to common shareholders	87,141	59,379	53,091
Income allocated to participating securities	973	720	463
Net income allocated to common shareholders	$ 86,168	$ 58,659	$ 52,628
Basic weighted average common shares outstanding	98,384,443	97,121,497	95,455,344
Diluted weighted average common shares outstanding	98,384,443	97,121,497	95,455,344
Basic EPS (in dollars per share)	$ 0.88	$ 0.60	$ 0.55
Diluted EPS (in dollars per share)	$ 0.88	$ 0.60	$ 0.55
Employee Non Employee Director Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from computation of earnings per share (in shares)	962,783	2,096,708	5,495,748
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Restricted Stock Units Excluded from Computation of Earning Per Share Amount	758,792	387,791	0