Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Calculation of earnings per share
Net income	$ 10,304		$ 2,301
Weighted average shares:
Basic weighted-average common shares outstanding	17,158,303		14,784,424
Dilutive effect of outstanding common stock equivalents	196,773	[1]	163,440	[1]
Diluted weighted-average number of common stock outstanding	17,355,076		14,947,864
Earnings per share:
Basic earnings (loss) per share	$ 0.60		$ 0.16
Diluted earnings (loss) per share	$ 0.59		$ 0.15

[1] Excluded from the computation of diluted earnings per share (due to their antidilutive effect) for the three months ended March 31, 2015 and 2014 were certain stock options and unvested restricted stock issued to key senior management personnel and directors of the Company. The aggregate number of common stock equivalents related to such options and unvested restricted shares, which could potentially be dilutive in future periods, was 102,382 and 106,266 at March 31, 2015 and 2014, respectively.