REVENUE - Disaggregation of Revenue by Product (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	$ 858,549	$ 711,556	$ 816,138
Lease Revenue	605	0
Total Revenue	859,154	711,556	816,138
Pulpwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	143,291	143,163	136,947
Sawtimber
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	449,178	439,473	499,966
Hardwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	2,430	5,259	3,433
Total Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	594,899	587,895	640,347
License Revenue, Primarily from Hunting
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	18,932	19,348	17,395
Other Non-Timber/Carbon Revenue
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	14,818	28,749	19,169
Agency Fee Income
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,160	677	652
Total Non-Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	34,910	48,774	37,216
Improved Development
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	14,498	5,882	8,336
Unimproved Development
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	8,426	19,476	8,621
Rural
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	67,152	47,647	46,280
Timberland & Non-Strategic
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	19,255	1,338	75,281
Conservation Easement
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	3,099
Deferred Revenue/Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	283	544	57
Large Dispositions
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	116,027
Total Real Estate Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	228,740	74,887	138,575
Trading | Total Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers			148,070
Elim.
Disaggregation of Revenue [Line Items]
Total Revenue	(3,676)	(155)	(92)
Operating Segments | Southern Timber
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	191,831	194,111	169,995
Total Revenue	191,831	194,111	169,995
Operating Segments | Southern Timber | Pulpwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	94,108	86,537	80,134
Operating Segments | Southern Timber | Sawtimber
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	73,683	67,360	60,295
Operating Segments | Southern Timber | Hardwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	2,430	5,259	3,433
Operating Segments | Southern Timber | Total Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	170,221	159,156	143,863
Operating Segments | Southern Timber | License Revenue, Primarily from Hunting
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	17,765	18,270	16,285
Operating Segments | Southern Timber | Other Non-Timber/Carbon Revenue
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	3,845	16,685	9,847
Operating Segments | Southern Timber | Agency Fee Income
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers			0
Operating Segments | Southern Timber | Total Non-Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	21,610	34,955	26,132
Operating Segments | Pacific Northwest Timber
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	120,809	85,414	109,832
Total Revenue	120,809	85,414	109,832
Operating Segments | Pacific Northwest Timber | Pulpwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	10,581	10,350	14,305
Operating Segments | Pacific Northwest Timber | Sawtimber
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	106,051	72,377	92,166
Operating Segments | Pacific Northwest Timber | Hardwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
Operating Segments | Pacific Northwest Timber | Total Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	116,632	82,727	106,471
Operating Segments | Pacific Northwest Timber | License Revenue, Primarily from Hunting
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	843	717	709
Operating Segments | Pacific Northwest Timber | Other Non-Timber/Carbon Revenue
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	3,334	1,970	2,652
Operating Segments | Pacific Northwest Timber | Agency Fee Income
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers			0
Operating Segments | Pacific Northwest Timber | Total Non-Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	4,177	2,687	3,361
Operating Segments | New Zealand Timber
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	202,315	241,861	249,014
Total Revenue	202,315	241,861	249,014
Operating Segments | New Zealand Timber | Pulpwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	27,558	32,925	28,737
Operating Segments | New Zealand Timber | Sawtimber
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	166,935	198,481	213,206
Operating Segments | New Zealand Timber | Hardwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
Operating Segments | New Zealand Timber | Total Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	194,493	231,406	241,943
Operating Segments | New Zealand Timber | License Revenue, Primarily from Hunting
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	307	361	401
Operating Segments | New Zealand Timber | Other Non-Timber/Carbon Revenue
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	7,515	10,094	6,670
Operating Segments | New Zealand Timber | Agency Fee Income
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers			0
Operating Segments | New Zealand Timber | Total Non-Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	7,822	10,455	7,071
Operating Segments | Timber Funds
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	26,120
Total Revenue	29,557	0	0
Operating Segments | Timber Funds | Pulpwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	784
Operating Segments | Timber Funds | Sawtimber
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	25,195
Operating Segments | Timber Funds | Hardwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0
Operating Segments | Timber Funds | Total Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	25,979	0	0
Operating Segments | Timber Funds | License Revenue, Primarily from Hunting
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	17
Operating Segments | Timber Funds | Other Non-Timber/Carbon Revenue
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	124
Operating Segments | Timber Funds | Total Non-Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	141
Operating Segments | Real Estate
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	228,740	74,887	138,575
Lease Revenue	605
Total Revenue	229,345	74,887	138,575
Operating Segments | Real Estate | Total Non-Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0
Operating Segments | Real Estate | Improved Development
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	14,498	5,882	8,336
Total Revenue	14,498	5,882	8,336
Operating Segments | Real Estate | Unimproved Development
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	8,426	19,476	8,621
Total Revenue	8,426	19,476	8,621
Operating Segments | Real Estate | Rural
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	67,152	47,647	46,280
Total Revenue	67,152	47,647	46,280
Operating Segments | Real Estate | Timberland & Non-Strategic
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	19,255	1,338	75,281
Operating Segments | Real Estate | Conservation Easement
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	3,099
Total Revenue	3,099	0	0
Operating Segments | Real Estate | Deferred Revenue/Other
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	283	544	57
Total Revenue	888	544	57
Operating Segments | Real Estate | Large Dispositions
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	116,027
Operating Segments | Real Estate | Total Real Estate Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	228,740	74,887	138,575
Operating Segments | Trading
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	88,734	115,283	148,722
Total Revenue	88,973	115,438	148,814
Operating Segments | Trading | Pulpwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	10,260	13,351	13,771
Operating Segments | Trading | Sawtimber
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	77,314	101,255	134,299
Operating Segments | Trading | Hardwood
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0
Operating Segments | Trading | Total Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	87,574	114,606	148,070
Operating Segments | Trading | License Revenue, Primarily from Hunting
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0		0
Operating Segments | Trading | Other Non-Timber/Carbon Revenue
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0		0
Operating Segments | Trading | Agency Fee Income
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,160	677	652
Operating Segments | Trading | Total Non-Timber Sales
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,160	677	652
Intersegment Eliminations | Timber Funds
Disaggregation of Revenue [Line Items]
Total Revenue	3,437
Intersegment Eliminations | Trading
Disaggregation of Revenue [Line Items]
Total Revenue	239	155	92
Intersegment Eliminations | Elim.
Disaggregation of Revenue [Line Items]
Total Revenue	$ (3,676)	$ (155)	$ (92)