Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2010	$ 164,982	$ 35	$ (86)	$ 155,791	$ 8,317	$ 925
Beginning Balance, Shares at Dec. 31, 2010		35,490,331	95,516
Net income	22,669				22,669
Issuance of capital shares
Restricted share grants, Shares		186,379
Exercised options	3,330	1		3,329
Exercised options, Shares		667,684
Repurchase of unvested shares of restricted common stock, Shares		(3,011)	3,011
Share based compensation	6,974			6,974
Tax benefit associated with options	1,354			1,354
Unrecognized actuarial loss, net of tax	(98)					(98)
Cumulative translation adjustment, net of tax	(850)					(850)
Ending Balance at Dec. 31, 2011	198,361	36	(86)	167,448	30,986	(23)
Ending Balance, Shares at Dec. 31, 2011		36,341,383	98,527
Net income	28,965				28,965
Issuance of capital shares
Restricted share grants		1		(1)
Restricted share grants, Shares		294,948
Exercised options	3,215			3,215
Exercised options, Shares		683,132
Repurchase of unvested shares of restricted common stock, Shares		(17,574)	17,574
Share based compensation	6,918			6,918
Tax benefit associated with options	1,101			1,101
Dividends declared	(2,971)				(2,971)
Unrecognized actuarial loss, net of tax	(665)					(665)
Cumulative translation adjustment, net of tax	182					182
Ending Balance at Dec. 31, 2012	235,106	37	(86)	178,681	56,980	(506)
Ending Balance, Shares at Dec. 31, 2012		37,301,889	116,101
Net income	31,085				31,085
Issuance of capital shares
Restricted share grants
Restricted share grants, Shares		276,279
Exercised options	16,109	2		16,107
Exercised options, Shares	1,788,274	1,788,274
Repurchase of unvested shares of restricted common stock, Shares		(13,729)	13,729
Purchase of treasury shares	(2,193)		(2,193)
Purchase of treasury shares, shares	75,000	(75,000)	75,000
Share based compensation	8,209			8,209
Tax benefit associated with options	6,379			6,379
Dividends declared	(9,324)				(9,324)
Unrecognized actuarial loss, net of tax	216					216
Cumulative translation adjustment, net of tax	1,288					1,288
Ending Balance at Dec. 31, 2013	$ 286,875	$ 39	$ (2,279)	$ 209,376	$ 78,741	$ 998
Ending Balance, Shares at Dec. 31, 2013		39,277,713	204,830