UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2012	$ 24,688	$ 184,023	$ (863)	$ 207,848
Balance (in shares) at Dec. 31, 2012	23,962
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	29,586	0	29,586
Other comprehensive income (loss), net of tax	0	0	3,457	3,457
Dividends declared	0	(8,647)	0	(8,647)
Dividends reinvested in common stock	475	0	0	475
Dividends reinvested in common stock (in shares)	20
Stock based compensation	1,938	0	0	1,938
Stock options exercised	1,186	0	0	1,186
Stock options exercised (in shares)	66
Common stock issued for share awards	0	0	0	0
Common stock issued for share awards (in shares)	68
Common stock issued	10	0	0	10
Common stock issued (in shares)	1
Common stock repurchased	(1,600)	0	0	(1,600)
Common stock repurchased (in shares)	(77)
Net excess tax benefit from stock options exercised	62	0	0	62
Balance at Dec. 31, 2013	26,759	204,962	2,594	234,315
Balance (in shares) at Dec. 31, 2013	24,040
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	8,616	0	8,616
Other comprehensive income (loss), net of tax	0	0	(347)	(347)
Stock based compensation	1,147	0	0	1,147
Stock options exercised	1,110	0	0	1,110
Stock options exercised (in shares)	50
Common stock issued for share awards	0	0	0	0
Common stock issued for share awards (in shares)	55
Common stock issued	2	0	0	2
Common stock issued (in shares)	1
Common stock repurchased	(1,540)	0	0	(1,540)
Common stock repurchased (in shares)	(50)
Net excess tax benefit from stock options exercised	305	0	0	305
Balance at Mar. 31, 2014	$ 27,783	$ 213,578	$ 2,247	$ 243,608
Balance (in shares) at Mar. 31, 2014	24,096