Shareholders' Equity (Statement of Equity) (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		$ 211,371,000			$ 211,371,000
Net income	$ 3,661,000		$ 4,160,000		7,773,000	$ 8,358,000
Other comprehensive income (loss), net of tax					$ (2,782,000)
Exercise of stock options (in shares)					135,507
Exercise of stock options					$ 1,944,000
Issuance of restricted common stock for services (in shares)	4,530	4,974	4,502	4,020
Issuance of restricted common stock for services	$ 97,000	$ 116,000	$ 105,000	$ 94,000	$ 213,000
Issuance of common stock under Employee Stock Purchase Plan (in shares)					19,737	16,428
Issuance of common stock under Employee Stock Purchase Plan					$ 365,000
Compensation cost of stock options					921,000
Balance	$ 219,805,000				$ 219,805,000
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance (in shares)		13,891,000			13,891,000
Balance		$ 139,000			$ 139,000
Exercise of stock options (in shares)					135,000
Exercise of stock options					$ 2,000
Issuance of restricted common stock for services (in shares)					9,000
Issuance of restricted common stock for services					$ 0
Issuance of common stock under Employee Stock Purchase Plan (in shares)					20,000
Issuance of common stock under Employee Stock Purchase Plan					$ 0
Balance (in shares)	14,055,000				14,055,000
Balance	$ 141,000				$ 141,000
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		76,126,000			76,126,000
Exercise of stock options					1,942,000
Issuance of restricted common stock for services					213,000
Issuance of common stock under Employee Stock Purchase Plan					365,000
Compensation cost of stock options					921,000
Balance	79,567,000				79,567,000
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		143,503,000			143,503,000
Net income					7,773,000
Balance	151,276,000				151,276,000
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance		$ (8,397,000)			(8,397,000)
Other comprehensive income (loss), net of tax					(2,782,000)
Balance	$ (11,179,000)				$ (11,179,000)