Acquisitions - Purchase Price Allocation (Details) - USD ($) $ in Thousands					12 Months Ended
	Oct. 30, 2017	Aug. 14, 2017	Jul. 05, 2017	Apr. 04, 2016	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Net Assets Acquired:
Goodwill					$ 258,174	$ 268,001	$ 151,455
Purchase Price:
Cash					$ 0	206,950	$ 58,894
2017 Acquisitions
Net Assets Acquired:
Cash and Cash Equivalents						2,219
Accounts Receivable						8,621
Inventories						27,337
Property, Plant & Equipment						14,475
Other Assets						2,447
Goodwill						101,788
Total assets acquired						242,399
Accounts Payable						5,328
Customer Deposits						7,496
Long-Term Deferred Income Taxes						16,622
Other Liabilities						5,771
Total Liabilities Assumed						35,217
Net assets acquired						207,182
Purchase Price:
Cash						2,993
Cash Paid to Seller Borrowed Under the Revolving Credit Facility						203,792
Estimated Post-closing Adjustment						397
Total purchase price						207,182
2017 Acquisitions | Tradenames
Net Assets Acquired:
Indefinite-Lived Intangible Assets						8,500
2017 Acquisitions | Customer relationships
Net Assets Acquired:
Definite-Lived Intangible Assets						54,182
2017 Acquisitions | Product technology
Net Assets Acquired:
Definite-Lived Intangible Assets						19,400
2017 Acquisitions | Other
Net Assets Acquired:
Definite-Lived Intangible Assets						3,430
NII FPG
Net Assets Acquired:
Cash and Cash Equivalents			$ 2,219
Accounts Receivable			6,542
Inventories			25,304
Property, Plant & Equipment			12,912
Other Assets			2,375
Goodwill			85,432
Total assets acquired			207,596
Accounts Payable			4,970
Customer Deposits			7,396
Long-Term Deferred Income Taxes			16,622
Other Liabilities			5,597
Total Liabilities Assumed			34,585
Net assets acquired			173,011
Purchase Price:
Cash			2,993
Cash Paid to Seller Borrowed Under the Revolving Credit Facility			170,018
Estimated Post-closing Adjustment			0
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			44,682
NII FPG | Product technology
Net Assets Acquired:
Definite-Lived Intangible Assets			17,100
NII FPG | Other
Net Assets Acquired:
Definite-Lived Intangible Assets			$ 2,530
Unaflex
Net Assets Acquired:
Cash and Cash Equivalents		$ 0
Accounts Receivable		2,079
Inventories		2,033
Property, Plant & Equipment		1,279
Other Assets		72
Goodwill		15,640
Total assets acquired		32,303
Accounts Payable		358
Customer Deposits		100
Long-Term Deferred Income Taxes		0
Other Liabilities		174
Total Liabilities Assumed		632
Net assets acquired		31,671
Purchase Price:
Cash		0
Cash Paid to Seller Borrowed Under the Revolving Credit Facility		31,274
Estimated Post-closing Adjustment		397
Total purchase price		31,671
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
Estimated Post-closing Adjustment	0
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