Earnings per Share (Computation of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended									12 Months Ended
		Dec. 31, 2015	[1]	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Net income		$ 1,692		$ 6,456	$ 7,193	$ 5,611	$ 6,088	$ 6,451	$ 6,316	$ 5,715	$ 20,952	$ 24,570	$ 22,783
Dividends and undistributed earnings allocated to participating securities	[2]										(59)	(75)	(64)
Net income available to common shareholders											$ 20,893	$ 24,495	$ 22,719
Weighted-average common shares outstanding for basic EPS											8,020,851	7,450,980	7,634,455
Dilutive effect of stock-based awards	[3]										28,857	19,613	18,815
Weighted-average common and potential common shares for diluted EPS											8,049,708	7,470,593	7,653,270
Basic EPS		$ 0.17		$ 0.86	$ 0.97	$ 0.75	$ 0.82	$ 0.87	$ 0.85	$ 0.76	$ 2.60	$ 3.29	$ 2.98
Diluted EPS		$ 0.17		$ 0.86	$ 0.96	$ 0.75	$ 0.82	$ 0.86	$ 0.85	$ 0.75	$ 2.60	$ 3.28	$ 2.97
Shares that were not considered in computation of potential common shares for purposes of diluted EPS	[4]										13,250	13,750	15,250

[1] On October 16, 2015, the Company completed its acquisition of SBM. Fourth quarter 2015 results of operations include revenues and expenses incurred as a combined organization from the acquisition date through December 31, 2015. The decrease in basic and diluted EPS in the fourth quarter of 2015 was due to acquisition costs and the issuance of 2.7 million shares of Company common stock in connection with the acquisition. Refer to Note 2 and 3 for additional details of the acquisition

[2] Represents dividends paid and undistributed earnings allocated to nonvested stock-based awards that contain non-forfeitable rights to dividends.

[3] Represents the effect of the assumed exercise of stock options, vesting of restricted shares, vesting of restricted stock units, and vesting of LTIP awards that have met the performance criteria, utilizing the treasury stock method.

[4] Represents stock-based awards not included in the computation of potential common shares for purposes of calculating diluted EPS as the exercise prices were greater than the average market price of the Company's common stock