Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]
Beginning Balance at Dec. 30, 2017	$ 634,807	$ 336	$ 44,812	$ 589,659
Beginning Balance, Shares at Dec. 30, 2017		33,571,524
Compensation expense under Incentive Stock Plan	898		898
Purchase and cancellation of common stock	(9,208)	$ (2)	(237)	(8,969)
Purchase and cancellation of common stock, Shares		(131,750)
Issuance of non-vested stock, net of cancellations	608	$ 1	607
Issuance of non-vested stock, net of cancellations, Shares		66,441
Other stock related activity, net of tax	(614)		(614)
Other stock related activity, net of tax, Shares		(2,716)
Net income	30,647			30,647
Ending Balance at Mar. 31, 2018	657,138	$ 335	45,466	611,337
Ending Balance, Shares at Mar. 31, 2018		33,503,499
Beginning Balance at Dec. 30, 2017	$ 634,807	$ 336	44,812	589,659
Beginning Balance, Shares at Dec. 30, 2017		33,571,524
Purchase and cancellation of common stock, Shares	(26,280)
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
Exercise of stock options	$ 31		31
Exercise of stock options, shares		11,714
Compensation expense under Incentive Stock Plan	915		915
Purchase and cancellation of common stock	$ (9,635)	$ (1)	(207)	(9,427)
Purchase and cancellation of common stock, Shares	(14,090)	(115,090)
Issuance of non-vested stock, net of cancellations, Shares		48,193
Other stock related activity, net of tax	$ (634)		1,290	(1,924)
Other stock related activity, net of tax, Shares		(7,665)
Net income	23,407			23,407
Ending Balance at Mar. 30, 2019	$ 741,707	$ 329	$ 49,890	$ 691,488
Ending Balance, Shares at Mar. 30, 2019	32,942,013	32,942,013