Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net income per share calculations for basic and diluted methods
Net income available to common stockholders (in dollars)	$ 10,444	$ 8,927	$ 27,778	$ 24,636
Shares:
Weighted average common shares outstanding	28,989,000	28,973,000	28,992,000	28,965,000
Dilutive effect of outstanding options, warrants and restricted stock units as determined by the application of the treasury stock method (in shares)	153,000	140,000	171,000	122,000
Weighted average common shares outstanding, as adjusted for diluted earnings per share calculation	29,142,000	29,113,000	29,163,000	29,087,000
Basic earnings per common share (in dollars per share)	$ 0.36	$ 0.31	$ 0.96	$ 0.85
Diluted earnings per common share (in dollars per share)	$ 0.36	$ 0.31	$ 0.95	$ 0.85
Stock options
Anti-dilutive securities excluded from the calculation of common stock equivalents
Number of anti-dilutive securities (in shares)			86,568	152,543
Warrants
Anti-dilutive securities excluded from the calculation of common stock equivalents
Number of anti-dilutive securities (in shares)			191,278	191,278
RSU
Anti-dilutive securities excluded from the calculation of common stock equivalents
Number of anti-dilutive securities (in shares)			112,433	117,992