Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 01, 2019	Oct. 02, 2018	Jul. 03, 2018	Apr. 03, 2018	Jan. 02, 2018	Oct. 03, 2017	Jul. 04, 2017	Apr. 04, 2017	Jan. 01, 2019	Jan. 02, 2018	Jan. 03, 2017
Quarterly Financial Data (unaudited)
Revenues	$ 585,155	$ 575,160	$ 587,319	$ 584,697	$ 571,815	$ 555,392	$ 569,869	$ 563,426	$ 2,332,331	$ 2,260,502	$ 2,275,719
Income from operations	19,359	33,495	34,543	31,551	22,747	34,317	50,218	43,563	118,948	152,845	200,993
Net income	$ 16,178	$ 28,475	$ 28,353	$ 26,029	$ 57,738	$ 26,445	$ 38,166	$ 35,043	$ 99,035	$ 157,392	$ 139,494
Basic net income per share (in dollars per share)	$ 0.36	$ 0.63	$ 0.62	$ 0.57	$ 1.26	$ 0.57	$ 0.80	$ 0.74	$ 2.19	$ 3.35	$ 2.91
Diluted net income per share (in dollars per share)	0.35	0.61	0.61	0.56	1.24	0.56	0.78	0.71	2.14	3.27	2.83
Cash dividends declared per common share (in dollars per share)	$ 0.33	$ 0.33	$ 0.29	$ 0.29	$ 0.29	$ 0.29	$ 0.24	$ 0.24	$ 1.24	$ 1.06	$ 0.88