Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Stock options excluded (in shares)	10,036	29,513	5,000	12,192	136,951
Net Income
Basic income available to common stockholders	$ 20,232	$ 14,176	$ 9,227	$ 43,929	$ 28,152
Diluted income available to common stockholders plus assumed conversions	$ 20,232	$ 14,176	$ 9,227	$ 43,929	$ 28,152
Shares
Basic income available to common stockholders (in shares)	39,709,565	39,586,524	27,387,123	35,652,626	26,776,140
Effect of dilutive stock option grants and warrants (in shares)	776,549	807,712	538,228	803,319	468,968
Diluted income available to common stockholders plus assumed conversions (in shares)	40,486,114	40,394,236	27,925,351	36,455,945	27,245,108
Per Share Amount
Basic income available to common stockholders (in dollars per share)	$ 0.51	$ 0.36	$ 0.34	$ 1.23	$ 1.05
Diluted income available to common stockholders plus assumed conversions (in dollars per share)	$ 0.50	$ 0.35	$ 0.33	$ 1.20	$ 1.03