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) Income, net of tax	Retained Earnings
Balance at Dec. 25, 2010	$ 165,588	$ 93	$ 41	$ 122,016	$ (438)	$ 43,876
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 $5,346 in 2011, $7,894 in 2012 and $5,282 in 2013 (in shares)		187,000
Stock options exercised and restricted shares activities, including tax benefit of $5,346 in 2011, $7,894 in 2012 and $5,282 in 2013	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 $207 in 2011, $75 in 2012 and $296 in 2013	(400)				(400)
Balance at Dec. 31, 2011	184,745	87	41	138,336	(838)	47,119
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 $5,346 in 2011, $7,894 in 2012 and $5,282 in 2013 (in shares)		154,000
Stock options exercised and restricted shares activities, including tax benefit of $5,346 in 2011, $7,894 in 2012 and $5,282 in 2013	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 $207 in 2011, $75 in 2012 and $296 in 2013	(45)				(45)
Balance at Dec. 29, 2012	245,091	87	41	157,305	(883)	88,541
Balance (in shares) at Dec. 29, 2012		8,704,000	4,107,000
Net income	70,392					70,392
Stock options exercised and restricted shares activities, including tax benefit of $5,346 in 2011, $7,894 in 2012 and $5,282 in 2013 (in shares)	89,070	132,000
Stock options exercised and restricted shares activities, including tax benefit of $5,346 in 2011, $7,894 in 2012 and $5,282 in 2013	8,403	1		8,402
Stock-based compensation expense	7,318			7,318
Repurchase of Class A Common Stock (in shares)	(195,728)	(196,000)
Repurchase of Class A Common Stock	(29,585)	(1)				(29,584)
Conversion from Class B to Class A (in shares)		145,000	(145,000)
Conversion from Class B to Class A		1	(1)
Defined benefit plans liability adjustment, net of tax of $207 in 2011, $75 in 2012 and $296 in 2013	466				466
Balance at Dec. 28, 2013	$ 302,085	$ 88	$ 40	$ 173,025	$ (417)	$ 129,349
Balance (in shares) at Dec. 28, 2013		8,785,000	3,962,000