SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Rollforward of Uncollectible Accounts (Details) - USD ($) $ in Thousands		9 Months Ended
	Jan. 01, 2020	Oct. 03, 2020	Sep. 28, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance, December 31, 2019	$ 9,962	$ 9,962
Cumulative effect of accounting change	$ 9,962	13,411
Provision for expected credit losses		3,762	$ (492)
Amounts charged against allowance for credit losses, net of recoveries		(1,801)
Allowance for credit losses of acquired company at date of acquisition		810
Ending balance, October 3, 2020		$ 13,411
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201613Member
Cumulative Effect, Period of Adoption, Adjustment
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Ending balance, December 31, 2019	$ 678	$ 678
Cumulative effect of accounting change	$ 678	$ 678