Acquisitions - Purchase Price Allocation (Details) - USD ($) $ in Thousands					3 Months Ended	12 Months Ended
	Oct. 30, 2017	Aug. 14, 2017	Jul. 05, 2017	Apr. 04, 2016	Dec. 30, 2017	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Net Assets Acquired:
Goodwill					$ 268,001	$ 268,001	$ 151,455	$ 119,051
Purchase Price:
Cash						206,950	$ 58,894	$ 0
2017 Acquisitions
Net Assets Acquired:
Cash and Cash Equivalents					2,219	2,219
Accounts Receivable					8,621	8,621
Inventories					26,950	26,950
Property, Plant & Equipment					14,390	14,390
Other Assets					2,447	2,447
Goodwill					101,881	101,881
Total assets acquired					242,048	242,048
Accounts Payable					5,328	5,328
Customer Deposits					7,496	7,496
Long-Term Deferred Income Taxes					16,668	16,668
Other Liabilities					5,771	5,771
Total Liabilities Assumed					35,263	35,263
Net assets acquired					206,785	206,785
Purchase Price:
Cash						2,993
Cash Paid to Seller Borrowed Under the Revolving Credit Facility						203,792
Total purchase price						206,785
2017 Acquisitions | Tradenames
Net Assets Acquired:
Indefinite-Lived Intangible Assets					8,500	8,500
2017 Acquisitions | Customer relationships
Net Assets Acquired:
Definite-Lived Intangible Assets					54,200	54,200
2017 Acquisitions | Product technology
Net Assets Acquired:
Definite-Lived Intangible Assets					19,400	19,400
2017 Acquisitions | Other
Net Assets Acquired:
Definite-Lived Intangible Assets					3,440	3,440
NII FPG
Net Assets Acquired:
Cash and Cash Equivalents			$ 2,219
Accounts Receivable			6,542
Inventories			25,246
Property, Plant & Equipment			12,912
Other Assets			2,375
Goodwill			85,508
Total assets acquired			207,642
Accounts Payable			4,970
Customer Deposits			7,396
Long-Term Deferred Income Taxes			16,668
Other Liabilities			5,597
Total Liabilities Assumed			34,631
Net assets acquired			173,011
Purchase Price:
Cash			2,993
Cash Paid to Seller Borrowed Under the Revolving Credit Facility			170,018
Total purchase price			173,011
NII FPG | Tradenames
Net Assets Acquired:
Indefinite-Lived Intangible Assets			8,500
NII FPG | Customer relationships
Net Assets Acquired:
Definite-Lived Intangible Assets			44,700
NII FPG | Product technology
Net Assets Acquired:
Definite-Lived Intangible Assets			17,100
NII FPG | Other
Net Assets Acquired:
Definite-Lived Intangible Assets			$ 2,540
Unaflex
Net Assets Acquired:
Cash and Cash Equivalents		$ 0
Accounts Receivable		2,079
Inventories		1,704
Property, Plant & Equipment		1,194
Other Assets		72
Goodwill		15,657
Total assets acquired		31,906
Accounts Payable		358
Customer Deposits		100
Long-Term Deferred Income Taxes		0
Other Liabilities		174
Total Liabilities Assumed		632
Net assets acquired		31,274
Purchase Price:
Cash		0
Cash Paid to Seller Borrowed Under the Revolving Credit Facility		31,274
Total purchase price		31,274
Unaflex | Tradenames
Net Assets Acquired:
Indefinite-Lived Intangible Assets		0
Unaflex | Customer relationships
Net Assets Acquired:
Definite-Lived Intangible Assets		8,000
Unaflex | Product technology
Net Assets Acquired:
Definite-Lived Intangible Assets		2,300
Unaflex | Other
Net Assets Acquired:
Definite-Lived Intangible Assets		$ 900
Other
Net Assets Acquired:
Cash and Cash Equivalents	$ 0
Accounts Receivable	0
Inventories	0
Property, Plant & Equipment	284
Other Assets	0
Goodwill	716
Total assets acquired	2,500
Accounts Payable	0
Customer Deposits	0
Long-Term Deferred Income Taxes	0
Other Liabilities	0
Total Liabilities Assumed	0
Net assets acquired	2,500
Purchase Price:
Cash	0
Cash Paid to Seller Borrowed Under the Revolving Credit Facility	2,500				$ 2,500
Total purchase price	2,500
Other | Tradenames
Net Assets Acquired:
Indefinite-Lived Intangible Assets	0
Other | Customer relationships
Net Assets Acquired:
Definite-Lived Intangible Assets	1,500
Other | Product technology
Net Assets Acquired:
Definite-Lived Intangible Assets	0
Other | Other
Net Assets Acquired:
Definite-Lived Intangible Assets	$ 0
PAAL
Net Assets Acquired:
Cash and Cash Equivalents				$ 2,277
Accounts Receivable				5,441
Inventories				3,947
Property, Plant & Equipment				7,179
Other Assets				2,882
Goodwill				38,552
Total assets acquired				84,969
Accounts Payable				5,536
Customer Deposits				2,471
Obligations Under Capital Lease				4,842
Long-Term Deferred Income Taxes				6,148
Other Liabilities				6,913
Total Liabilities Assumed				25,910
Net assets acquired				59,059
Purchase Price:
Cash				29,193		$ 165
Cash Paid to Seller Borrowed Under the Revolving Credit Facility				29,866
Total purchase price				59,059
PAAL | Customer relationships
Net Assets Acquired:
Definite-Lived Intangible Assets				15,831
PAAL | Product technology
Net Assets Acquired:
Definite-Lived Intangible Assets				4,203
PAAL | Tradenames
Net Assets Acquired:
Definite-Lived Intangible Assets				2,278
PAAL | Other
Net Assets Acquired:
Definite-Lived Intangible Assets				$ 2,379