Summary of Significant Accounting Policies - Calculation Of Earnings Per Share (Details) (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
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Net income	$ 6,674	$ 3,707	$ 4,369	$ 2,658	$ 2,681	$ 3,474	$ 3,496	$ 2,674	$ 17,408	$ 12,325	$ 12,946
Basic weighted average common shares outstanding									6,761,328	6,518,772	6,477,266
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									91,000	91,000	98,000
Total									6,852,267	6,609,950	6,574,993
Earnings per share, basic (USD per share)	$ 0.98	$ 0.54	$ 0.64	$ 0.41	$ 0.41	$ 0.53	$ 0.54	$ 0.41	$ 2.57	$ 1.89	$ 2.00
Earnings per share, diluted (USD per share)	$ 0.97	$ 0.53	$ 0.63	$ 0.40	$ 0.40	$ 0.53	$ 0.53	$ 0.41	$ 2.54	$ 1.87	$ 1.97