ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES - Balance sheet (Details) - USD ($) $ in Thousands	Mar. 28, 2020	Dec. 28, 2019
Condensed Balance Sheet Statements, Captions [Line Items]
Prepaid expenses and other current assets	$ 19,855	$ 19,644
Operating lease right-of-use assets	36,272	37,768
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accrued expenses and other current liabilities	45,775	42,088
Current operating lease liabilities	7,867	7,768
Noncurrent operating lease liabilities	40,372	$ 42,200
No. 2016-02
Condensed Balance Sheet Statements, Captions [Line Items]
Prepaid expenses and other current assets	20,814
Operating lease right-of-use assets	33,668
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accrued expenses and other current liabilities	43,749
Current operating lease liabilities	5,350
Noncurrent operating lease liabilities	40,638
Other liabilities	3,247
As Previously Reported | No. 2016-02
Condensed Balance Sheet Statements, Captions [Line Items]
Prepaid expenses and other current assets	20,069
Operating lease right-of-use assets	0
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accrued expenses and other current liabilities	44,583
Current operating lease liabilities	0
Noncurrent operating lease liabilities	0
Other liabilities	13,988
Impact of Adoption | No. 2016-02
Condensed Balance Sheet Statements, Captions [Line Items]
Prepaid expenses and other current assets	745
Operating lease right-of-use assets	33,668
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accrued expenses and other current liabilities	(834)
Current operating lease liabilities	5,350
Noncurrent operating lease liabilities	40,638
Other liabilities	$ (10,741)