Earnings Per Share - Reconciles Numerators and Denominators of Basic Earnings Per Share with Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator for Earnings per Share-Basic:
Net income	$ 18,188	$ 16,093
Less: Income allocated to participating shares	60	41
Net Income Allocated to Shareholders	18,128	16,052
Net Income Available to Shareholders	$ 18,188	$ 16,093
Denominators for Earnings per Share:
Weighted Average Shares Outstanding-Basic	34,690,250	34,661,016
Add: Potentially dilutive shares	222,011	78,498
Denominator for Treasury Stock Method-Diluted (in shares)	34,912,261	34,739,514
Weighted Average Shares Outstanding-Basic	34,690,250	34,661,016
Add: Average participating shares outstanding	115,395	88,265
Denominator for Two-Class Method-Diluted (in shares)	34,805,645	34,749,281
Earnings per share—basic (in dollars per share)	$ 0.52	$ 0.46
Earnings per share—diluted (in dollars per share)	0.52	0.46
Anti-dilutive warrants - exercise price (in dollars per share)	$ 31.53	$ 31.53
Warrants
Denominators for Earnings per Share:
Anti-dilutive excluded from potentially dilutive shares	447,103	517,012
Restricted Stock
Denominators for Earnings per Share:
Anti-dilutive excluded from potentially dilutive shares	79,544	81,840