Earnings Per Share (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Income
Net income									$ 16,616	$ 8,993	$ 15,776
Basic income available to common stockholders	3,891	5,450	4,643	2,632	4,204	3,066	(249)	1,972	16,616	8,993	15,776
Diluted income available to common stockholders plus assumed conversions									$ 16,616	$ 8,993	$ 15,776
Shares
Basic income available to common stockholders (in shares)									17,046,660	15,798,885	10,571,073
Effect of dilutive stock options (in shares)									297,317	811,069	412,961
Diluted income available to common stockholders plus assumed conversions (in shares)									17,343,977	16,609,954	10,984,034
Per Share Amount
Basic income available to common stockholders (in dollars per share)	$ 0.22	$ 0.32	$ 0.28	$ 0.15	$ 0.26	$ 0.19	$ (0.02)	$ 0.14	$ 0.97	$ 0.57	$ 1.49
Diluted income available to common stockholders plus assumed conversions (in dollars per share)	$ 0.23	$ 0.31	$ 0.27	$ 0.15	$ 0.25	$ 0.18	$ (0.02)	$ 0.13	$ 0.96	$ 0.54	$ 1.44