Acquisitions and Divestitures - Schedule of Consolidated Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Jan. 01, 2017	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016
Business Acquisition [Line Items]
Net sales	$ 1,126,149	$ 1,162,526	$ 1,169,291	$ 865,702	$ 841,560	$ 849,028	$ 840,384	$ 625,456	$ 4,323,668	$ 3,156,428	$ 2,306,458
Income from operations									96,179	127,859	98,144
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | BYB Brands Inc [Member]
Business Acquisition [Line Items]
Net sales											23,875
Income from operations											1,809
2015 Expansion Territories & 2015 Asset Exchange [Member]
Business Acquisition [Line Items]
Net sales									484,485	469,440	278,691
Income from operations									1,540	1,907	3,364
2016 System Transformation Transactions [Member]
Business Acquisition [Line Items]
Net sales									1,011,638	592,329
Income from operations									18,930	22,373
2017 System Transformation Transactions [Member]
Business Acquisition [Line Items]
Net sales									740,259
Income from operations									10,754
2015 Expansion Territories and 2016 and 2017 System Transformation Transactions and 2015 Asset Exchange [Member]
Business Acquisition [Line Items]
Net sales									2,236,382	1,061,769	278,691
Income from operations									$ 31,224	$ 24,280	$ 3,364