DEBT (Schedule of Long Term Debt) (Details) - USD ($) $ in Thousands		9 Months Ended
	Jan. 01, 2021	Sep. 30, 2020	Sep. 01, 2020	Aug. 31, 2020	May 07, 2020	Apr. 16, 2020	Apr. 01, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, net of deferred financing costs		$ 1,378,596
Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		1,320,872
Less: Deferred financing costs		(2,667)
Long-term debt, net of deferred financing costs		1,318,205						$ 973,129
Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		60,403
Less: Deferred financing costs		(12)
Long-term debt, net of deferred financing costs		$ 60,391						$ 0
Term Credit Agreement borrowings due 2028 at a variable interest rate of 1.8% at June 30, 2020
Debt Instrument [Line Items]
Debt instrument, interest rate during period		3.20%
Term Credit Agreement borrowings due 2028 at a variable interest rate of 1.8% at June 30, 2020 | LIBOR
Debt Instrument [Line Items]
Basis points on periodic interest rate		1.60%
Term Credit Agreement borrowings due 2028 at a variable interest rate of 1.8% at June 30, 2020 | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 350,000
Less: Deferred financing costs							$ (500)
Effective fixed interest rate		1.80%
Senior Notes due 2022 at a fixed interest rate of 3.75%
Debt Instrument [Line Items]
Stated fixed interest rate					3.75%
Senior Notes due 2022 at a fixed interest rate of 3.75% | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 325,000
Stated fixed interest rate		3.75%
Incremental Term Loan Agreement borrowings due 2026 at a variable interest rate of 2.1% at June 30, 2020
Debt Instrument [Line Items]
Debt instrument, interest rate during period		2.80%
Incremental Term Loan Agreement borrowings due 2026 at a variable interest rate of 2.1% at June 30, 2020 | LIBOR
Debt Instrument [Line Items]
Basis points on periodic interest rate		1.90%
Incremental Term Loan Agreement borrowings due 2026 at a variable interest rate of 2.1% at June 30, 2020 | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 300,000
Effective fixed interest rate		2.10%
2020 Incremental Term Loan Agreement borrowings due 2025 at an average variable interest rate of 2.05% at June 30, 2020
Debt Instrument [Line Items]
Debt instrument, interest rate during period		2.30%
2020 Incremental Term Loan Agreement borrowings due 2025 at an average variable interest rate of 2.05% at June 30, 2020 | LIBOR
Debt Instrument [Line Items]
Basis points on periodic interest rate		1.85%
2020 Incremental Term Loan Agreement borrowings due 2025 at an average variable interest rate of 2.05% at June 30, 2020 | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 250,000
Less: Deferred financing costs						$ (800)
Effective fixed interest rate		2.00%
Revolving Credit Facility borrowings due 2025 at an average variable interest rate of 1.7% at September 30, 2020 | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 20,000
Effective fixed interest rate		1.70%
New Zealand subsidiary noncontrolling interest shareholder loan due 2025 at a fixed interest rate of 2.95% | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 22,735
Stated fixed interest rate		2.95%
Due 2025 at a fixed interest rate of 6.1% | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 11,690
Stated fixed interest rate		6.10%
Due 2028 at a fixed interest rate of 4.1% | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 12,052
Stated fixed interest rate		4.10%
Due 2033 at a fixed interest rate of 5.3% | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 19,497
Stated fixed interest rate		5.30%
Due 2036 at a fixed interest rate of 5.4% | Excluding Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 9,898
Stated fixed interest rate		5.40%
Due 2022 at a fixed interest rate of 2.0% | Timber Funds | LIBOR | Forecast
Debt Instrument [Line Items]
Basis points on periodic interest rate	1.70%
Fund II Mortgages Payable, Due September 2022 At 2.0% One | Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 11,000	$ 11,000
Stated fixed interest rate		2.00%	2.00%	4.90%
Fund II Mortgages Payable, Due September 2022 At 2.0% Two | Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 14,000	$ 14,000
Stated fixed interest rate		2.00%	2.00%	3.80%
Due 2023 at a fixed interest rate of 5.1% | Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 19,695
Stated fixed interest rate		5.10%
Due 2024 at a fixed interest rate of 4.5% | Timber Funds
Debt Instrument [Line Items]
Total debt, excluding Timber Funds		$ 15,708
Stated fixed interest rate		4.50%