Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenues	$ 247,889	$ 208,651
Costs and expenses:
Operating	166,016	144,623
Selling	46,304	39,657
General and administrative	19,044	17,718
Depreciation and amortization	14,212	13,121
Gain on sale of assets, net	(653)	(802)
Total costs and expenses	244,923	214,317
Income (loss) from operations	2,966	(5,666)
Other income (expense):
Interest expense	(2,151)	(1,401)
Interest income	83	78
Other, net	(1,655)	(1,662)
Loss before income taxes	(757)	(8,651)
Income tax benefit	(264)	(2,024)
Net loss	$ (493)	$ (6,627)
Net income per share:
Net loss per share--basic and diluted	$ (0.02)	$ (0.26)
Weighted-average shares outstanding:
Weighted-average shares outstanding--basic and diluted	23,072	25,418
Basic	23,072	25,418
Diluted	24,018	26,476
Dividends declared per share	$ 0.025	$ 0.025