MERGER WITH POPE RESOURCES - Narrative (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	May 08, 2020 fund
Business Acquisition [Line Items]
Costs related to the merger with Pope Resources	$ 0	$ 13,498		$ 0	$ 15,985
Net (loss) income	$ 63,420	455		78,452	26,876
Merger with Pope Resources
Business Acquisition [Line Items]
Number of timber funds acquired | fund						3
Costs related to the merger with Pope Resources		13,500	$ 2,500
Increase in higher and better use timberlands from purchase price allocation				8,200
Increase (decrease) in timber and timberlands				1,100
Merger with Pope Resources | Acquisition-related Transaction Costs
Business Acquisition [Line Items]
Net (loss) income		$ 23,500			$ 31,200
Core Timberlands
Business Acquisition [Line Items]
Increase (decrease) in timber and timberlands				(15,500)
Timber Funds
Business Acquisition [Line Items]
Increase (decrease) in timber and timberlands				$ 16,600