Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 29,199	$ 21,259
Earnings allocated to participating securities - preferred shares	3	39
Earnings allocated to participating securities - nonvested restricted shares	397	247
Earnings allocated to common shareholders, Basic	$ 28,799	$ 20,973
Weighted average common shares outstanding	57,388	57,114
Basic earnings per common share	$ 0.50	$ 0.37
Earnings allocated to common shareholders, Diluted	$ 28,799	$ 20,973
Dilutive effect of equity awards and warrants	6	11
Weighted average diluted common shares outstanding	57,394	57,125
Diluted earnings per common share	$ 0.50	$ 0.37
Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive.	14	27