REVENUE (Disaggregation of Revenue by Contract Type) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Total Timber Sales	$ 202,970	$ 194,198
Stumpage Pay-as-Cut
Disaggregation of Revenue [Line Items]
Total Timber Sales	22,511	20,102
Stumpage Lump Sum
Disaggregation of Revenue [Line Items]
Total Timber Sales	6,924	5,377
Stumpage Agreed Volume
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	1,180
Total Stumpage
Disaggregation of Revenue [Line Items]
Total Timber Sales	29,435	26,659
Total Delivered
Disaggregation of Revenue [Line Items]
Total Timber Sales	128,864	105,565
Total Delivered | Domestic
Disaggregation of Revenue [Line Items]
Total Timber Sales	59,798	50,700
Total Delivered | Export
Disaggregation of Revenue [Line Items]
Total Timber Sales	69,066	54,865
Timber
Disaggregation of Revenue [Line Items]
Total Timber Sales	158,299	132,224
Southern Timber
Disaggregation of Revenue [Line Items]
Total Timber Sales		38,935
Southern Timber | Stumpage Pay-as-Cut
Disaggregation of Revenue [Line Items]
Total Timber Sales	22,511	20,102
Southern Timber | Stumpage Lump Sum
Disaggregation of Revenue [Line Items]
Total Timber Sales	1,818	2,797
Southern Timber | Stumpage Agreed Volume
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
Southern Timber | Total Stumpage
Disaggregation of Revenue [Line Items]
Total Timber Sales	24,329	22,899
Southern Timber | Total Delivered
Disaggregation of Revenue [Line Items]
Total Timber Sales	13,811	9,816
Southern Timber | Total Delivered | Domestic
Disaggregation of Revenue [Line Items]
Total Timber Sales	13,377	9,816
Southern Timber | Total Delivered | Export
Disaggregation of Revenue [Line Items]
Total Timber Sales	434	0
Southern Timber | Timber
Disaggregation of Revenue [Line Items]
Total Timber Sales		32,715
Pacific Northwest Timber
Disaggregation of Revenue [Line Items]
Total Timber Sales		25,835
Pacific Northwest Timber | Stumpage Pay-as-Cut
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
Pacific Northwest Timber | Stumpage Lump Sum
Disaggregation of Revenue [Line Items]
Total Timber Sales	5,106	2,580
Pacific Northwest Timber | Stumpage Agreed Volume
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	1,180
Pacific Northwest Timber | Total Stumpage
Disaggregation of Revenue [Line Items]
Total Timber Sales	5,106	3,760
Pacific Northwest Timber | Total Delivered
Disaggregation of Revenue [Line Items]
Total Timber Sales	25,381	21,032
Pacific Northwest Timber | Total Delivered | Domestic
Disaggregation of Revenue [Line Items]
Total Timber Sales	25,381	21,032
Pacific Northwest Timber | Total Delivered | Export
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
Pacific Northwest Timber | Timber
Disaggregation of Revenue [Line Items]
Total Timber Sales		24,792
New Zealand Timber
Disaggregation of Revenue [Line Items]
Total Timber Sales		40,874
New Zealand Timber | Stumpage Pay-as-Cut
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
New Zealand Timber | Stumpage Lump Sum
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
New Zealand Timber | Stumpage Agreed Volume
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
New Zealand Timber | Total Stumpage
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
New Zealand Timber | Total Delivered
Disaggregation of Revenue [Line Items]
Total Timber Sales	50,589	40,740
New Zealand Timber | Total Delivered | Domestic
Disaggregation of Revenue [Line Items]
Total Timber Sales	20,103	18,845
New Zealand Timber | Total Delivered | Export
Disaggregation of Revenue [Line Items]
Total Timber Sales	30,486	21,895
New Zealand Timber | Timber
Disaggregation of Revenue [Line Items]
Total Timber Sales		40,740
Trading
Disaggregation of Revenue [Line Items]
Total Timber Sales		34,265
Trading | Stumpage Pay-as-Cut
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
Trading | Stumpage Lump Sum
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
Trading | Stumpage Agreed Volume
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
Trading | Total Stumpage
Disaggregation of Revenue [Line Items]
Total Timber Sales	0	0
Trading | Total Delivered
Disaggregation of Revenue [Line Items]
Total Timber Sales	39,083	33,977
Trading | Total Delivered | Domestic
Disaggregation of Revenue [Line Items]
Total Timber Sales	937	1,007
Trading | Total Delivered | Export
Disaggregation of Revenue [Line Items]
Total Timber Sales	$ 38,146	32,970
Trading | Timber
Disaggregation of Revenue [Line Items]
Total Timber Sales		$ 33,977