Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]
Beginning Balance at Dec. 26, 2015	$ 518,036	$ 349	$ 42,799	$ 474,888
Beginning Balance, Shares at Dec. 26, 2015		34,863,396
Compensation expense under Incentive Stock Plan	2,380		2,380
Purchase and cancellation of common stock	$ (24,678)	$ (5)	(846)	(23,827)
Purchase and cancellation of common stock, Shares	(38,970)	(469,836)
Issuance of non-vested stock, net of cancellations		$ 1	(1)
Issuance of non-vested stock, net of cancellations, Shares		131,123
Other stock related activity, net of tax	$ (145)		(145)
Other stock related activity, net of tax, Shares		(7,050)
Net income	106,049			106,049
Ending Balance at Dec. 31, 2016	601,642	$ 345	44,187	557,110
Ending Balance, Shares at Dec. 31, 2016		34,517,633
Exercise of stock options	31		31
Exercise of stock options, shares		29,750
Compensation expense under Incentive Stock Plan	3,162		3,162
Purchase and cancellation of common stock	$ (76,129)	$ (10)	(1,848)	(74,271)
Purchase and cancellation of common stock, Shares	(19,110)	(1,025,475)
Issuance of non-vested stock, net of cancellations	$ 675	$ 1	674
Issuance of non-vested stock, net of cancellations, Shares		65,317
Other stock related activity, net of tax	(1,173)		(1,394)	221
Other stock related activity, net of tax, Shares		(15,701)
Net income	106,599			106,599
Ending Balance at Dec. 30, 2017	$ 634,807	$ 336	44,812	589,659
Ending Balance, Shares at Dec. 30, 2017	33,571,524	33,571,524
Exercise of stock options	$ 200		200
Exercise of stock options, shares		10,572
Compensation expense under Incentive Stock Plan	3,460		3,460
Purchase and cancellation of common stock	$ (45,351)	$ (7)	(1,167)	(44,177)
Purchase and cancellation of common stock, Shares	(26,280)	(648,503)
Issuance of non-vested stock, net of cancellations	$ 1,799	$ 1	1,798
Issuance of non-vested stock, net of cancellations, Shares		83,891
Other stock related activity, net of tax	(894)		(1,242)	348
Other stock related activity, net of tax, Shares		(12,623)
Net income	133,602			133,602
Ending Balance at Dec. 29, 2018	$ 727,623	$ 330	$ 47,861	$ 679,432
Ending Balance, Shares at Dec. 29, 2018	33,004,861	33,004,861