Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Calculation of Earnings per share
Net income	$ 6,645	$ 12,451	$ 11,186	$ 23,141
Weighted average common shares outstanding (in shares)	25,481	21,456	24,877	21,418
Effect of dilutive stock options and warrants (in shares)	480	1,626	524	1,616
Weighted average common shares outstanding – diluted (in shares)	25,961	23,082	25,401	23,034
Basic (in dollars per share)	$ 0.26	$ 0.58	$ 0.45	$ 1.08
Diluted (in dollars per share)	$ 0.26	$ 0.54	$ 0.44	$ 1.00