Consolidated Statements Of Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common Class A	Common Class B	Additional Paid-in Capital	Accumulated Other Comprehensive Loss, net of tax	Retained Earnings
Beginning balance at Dec. 26, 2009	$ 173,155	$ 101	$ 41	$ 111,668	$ (359)	$ 61,704
Beginning balance (in shares) at Dec. 26, 2009		10,143,000	4,107,000
Net income	50,142					50,142
Stock options exercised and restricted shares activities, including tax benefit of $7,894 in 2012, $5,346 in 2011 and $3,014 in 2010 (in shares)		247,000
Stock options exercised and restricted shares activities, including tax benefit of $7,894 in 2012, $5,346 in 2011 and $3,014 in 2010	7,227	3		7,224
Stock-based compensation expense	3,124			3,124
Repurchase of Class A Common Stock (in shares)	(1,101,708)	(1,102,000)
Repurchase of Class A Common Stock	(67,981)	(11)				(67,970)
Defined benefit plans liability adjustment, net of tax of $75 in 2012, $207 in 2011 and $48 in 2010	(79)				(79)
Ending balance at Dec. 25, 2010	165,588	93	41	122,016	(438)	43,876
Ending balance (in shares) at Dec. 25, 2010		9,288,000	4,107,000
Net income	66,059					66,059
Stock options exercised and restricted shares activities, including tax benefit of $7,894 in 2012, $5,346 in 2011 and $3,014 in 2010 (in shares)		187,000
Stock options exercised and restricted shares activities, including tax benefit of $7,894 in 2012, $5,346 in 2011 and $3,014 in 2010	10,144	2		10,142
Stock-based compensation expense	6,178			6,178
Repurchase of Class A Common Stock (in shares)	(760,036)	(760,000)
Repurchase of Class A Common Stock	(62,824)	(8)				(62,816)
Defined benefit plans liability adjustment, net of tax of $75 in 2012, $207 in 2011 and $48 in 2010	(400)				(400)
Ending balance at Dec. 31, 2011	184,745	87	41	138,336	(838)	47,119
Ending balance (in shares) at Dec. 31, 2011		8,715,000	4,107,000
Net income	59,467					59,467
Stock options exercised and restricted shares activities, including tax benefit of $7,894 in 2012, $5,346 in 2011 and $3,014 in 2010 (in shares)	245,965	154,000
Stock options exercised and restricted shares activities, including tax benefit of $7,894 in 2012, $5,346 in 2011 and $3,014 in 2010	12,443	2		12,441
Stock-based compensation expense	6,528			6,528
Repurchase of Class A Common Stock (in shares)	(165,192)	(165,000)
Repurchase of Class A Common Stock	(18,047)	(2)				(18,045)
Defined benefit plans liability adjustment, net of tax of $75 in 2012, $207 in 2011 and $48 in 2010	(45)				(45)
Ending balance at Dec. 29, 2012	$ 245,091	$ 87	$ 41	$ 157,305	$ (883)	$ 88,541
Ending balance (in shares) at Dec. 29, 2012		8,704,000	4,107,000