Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
	Feb. 18, 2020	Dec. 31, 2019	Oct. 01, 2019	Jul. 02, 2019	Apr. 02, 2019	Jan. 01, 2019	Oct. 02, 2018	Jul. 03, 2018	Apr. 03, 2018	Dec. 31, 2019	Jan. 01, 2019	Jan. 02, 2018	Jan. 03, 2017
Quarterly Financial Data (unaudited)
Revenues		$ 694,030	$ 586,536	$ 602,645	$ 599,481	$ 585,155	$ 575,160	$ 587,319	$ 584,697	$ 2,482,692	$ 2,332,331	$ 2,260,502
Income from operations		6,387	26,964	40,099	30,148	19,359	33,495	34,543	31,551	103,598	118,948	152,845
Net income		$ 48,709	$ 16,090	$ 35,510	$ 26,984	$ 16,178	$ 28,475	$ 28,353	$ 26,029	$ 127,293	$ 99,035	$ 157,392
Basic net income per share (in dollars per share)		$ 1.11	$ 0.37	$ 0.80	$ 0.61	$ 0.36	$ 0.63	$ 0.62	$ 0.57	$ 2.90	$ 2.19	$ 3.35
Diluted net income per share (in dollars per share)		1.10	0.36	0.79	0.60	0.35	0.61	0.61	0.56	2.86	2.14	3.27
Cash dividends declared per common share (in dollars per share)	$ 0.36	$ 0.36	$ 0.36	$ 0.33	$ 0.33	$ 0.33	$ 0.33	$ 0.29	$ 0.29	$ 1.38	$ 1.24	$ 1.06	$ 1.06