DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES - Narrative (Details)				12 Months Ended
	Mar. 11, 2019 USD ($) swap	Feb. 28, 2019 USD ($)	Dec. 28, 2018 USD ($) swap	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) swap	Aug. 13, 2015 USD ($) swap
Derivative [Line Items]
Number of swaps terminated | swap	2		1			7
Proceeds from termination payments, net of fees	$ 1,302,000		$ 684,000			$ 973,000
Notional amount of terminated swaps	120,000,000		50,000,000			215,000,000
Amounts reclassified to interest expense upon interest rate hedge termination				$ 1,806,000	$ 1,552,000	0
Write-off of terminated interest rate swaps				1,580,000
Change in fair value of swaps				209,000	1,728,000	0
Increase in interest expense related to change in fair value of interest rate swaps					$ 1,728,000
Interest rate swaps
Derivative [Line Items]
Number of interest rate swaps | swap							10
Derivative, notional amount							$ 385,000,000
Derivative, fair value	1,421,000
Derivative, gain (loss) on derivative, net				$ (119,000)
Unsecured term facility entered into in May 2015
Derivative [Line Items]
Repayments of debt						$ 215,000,000
Revolving Credit Facility | Line of Credit
Derivative [Line Items]
Repayments of debt	$ 120,000,000	$ 10,000,000	$ 40,000,000