Earnings per Common Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Earnings Per Share [Abstract]
Net Income	$ 24,361		$ 19,844
Earnings allocated to participating securities - nonvested restricted shares	225		169
Earnings allocated to participating securities - preferred shares	43		40
Earnings allocated to common shareholders, Basic	24,093		19,635
Weighted average common shares outstanding	56,965		51,097
Basic earnings per common share	$ 0.42		$ 0.38
Dilutive effect of equity awards and warrants	13		1,336
Earnings allocated to common shareholders, Diluted	$ 24,093	[1]	$ 19,639	[1]
Weighted average diluted common shares outstanding	56,978		52,433
Diluted earnings per common share	$ 0.42		$ 0.37
Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive.	53		83

[1] Earnings allocated to common shareholders for basic and diluted EPS may differ under the two-class method as a result of adding common stock equivalents for options and warrants to dilutive shares outstanding, which alters the ratio used to allocate earnings to common shareholders and participating securities for the purposes of calculating diluted EPS.