Segment Information (Summary of Information by Business Segment) (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended
		Mar. 31, 2022	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Adjusted EBITDDA			$ 245,562	$ 194,986
Interest expense, net	[1]		(2,894)	(3,574)
Depreciation, depletion and amortization			(19,502)	(17,996)
Basis of real estate sold			10,854	8,823
Net loss on fire damage			(276)
Pension settlement charge		$ (14,165)	(14,165)
Non-operating pension and other postretirement employee benefits			(1,929)	(3,414)
Gain (loss) on disposal of fixed assets			(3)	34
Income before income taxes			195,945	161,145
Bond discounts and deferred loan fees	[1]		372	403
Total depreciation, depletion and amortization			19,874	18,399
Operating Segments [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion and amortization			19,502	17,996
Operating Segments [Member] | Timberlands [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDDA			76,434	67,858
Depreciation, depletion and amortization			12,161	11,417
Operating Segments [Member] | Wood Products [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDDA			149,951	125,555
Depreciation, depletion and amortization			7,021	6,203
Operating Segments [Member] | Real Estate Segment [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDDA			30,124	16,593
Depreciation, depletion and amortization			170	155
Basis of real estate sold			10,860	8,829
Corporate [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDDA			(9,584)	(10,710)
Depreciation, depletion and amortization			150	221
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDDA			1,363	(4,310)
Basis of real estate sold			$ (6)	$ (6)

[1] Bond discounts and deferred loan fees are reported within interest expense, net on the Condensed Consolidated Statements of Operations.