Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]
Beginning Balance at Dec. 29, 2012	$ 332,872	$ 365	$ 41,007	$ 291,500
Beginning Balance, Shares at Dec. 29, 2012		36,477,506
Exercise of stock options	551	$ 1	550
Exercise of stock options, shares		93,509
Compensation expense under Incentive Stock Plan	960		960
Purchase and cancellation of common stock	$ (3,489)	$ (1)	(142)	(3,346)
Purchase and cancellation of common stock, Shares	(78,580)	(78,580)
Issuance of non-vested stock, net of cancellations	$ 0	$ 0	0	0
Issuance of non-vested stock, net of cancellations, Shares		(17,626)
Other stock related activity, net of tax	827		744	83
Other stock related activity, net of tax, Shares		(9,851)
Net income	81,920			81,920
Ending Balance at Dec. 28, 2013	413,641	$ 365	43,119	370,157
Ending Balance, Shares at Dec. 28, 2013		36,464,958
Exercise of stock options	463	$ 1	462
Exercise of stock options, shares		66,500
Compensation expense under Incentive Stock Plan	1,146		1,146
Purchase and cancellation of common stock	$ (43,519)	$ (9)	(1,651)	(41,859)
Purchase and cancellation of common stock, Shares	(61,830)	(917,430)
Issuance of non-vested stock, net of cancellations	$ 0	$ 0	0	0
Issuance of non-vested stock, net of cancellations, Shares		5,060
Other stock related activity, net of tax	343	$ (1)	337	7
Other stock related activity, net of tax, Shares		(7,850)
Net income	89,987			89,987
Ending Balance at Dec. 27, 2014	$ 462,061	$ 356	43,413	418,292
Ending Balance, Shares at Dec. 27, 2014	35,611,238	35,611,238
Exercise of stock options	$ 93		93
Exercise of stock options, shares		31,305
Compensation expense under Incentive Stock Plan	882		882
Purchase and cancellation of common stock	$ (37,324)	$ (7)	(1,406)	(35,911)
Purchase and cancellation of common stock, Shares	(33,430)	(781,130)
Issuance of non-vested stock, net of cancellations	$ 0	$ 0	0	0
Issuance of non-vested stock, net of cancellations, Shares		8,922
Other stock related activity, net of tax	(5)		(183)	178
Other stock related activity, net of tax, Shares		(6,939)
Net income	92,329			92,329
Ending Balance at Dec. 26, 2015	$ 518,036	$ 349	$ 42,799	$ 474,888
Ending Balance, Shares at Dec. 26, 2015	34,863,396	34,863,396