Segment Information (Summary of Revenues by Major Product) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Revenues		$ 287,330	$ 313,046	$ 1,089,029	$ 703,481
Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues		330,800	353,427	1,227,212	798,487
Intersegment Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Revenues	[1]	(43,470)	(40,381)	(138,183)	(95,006)
Timberlands [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues		129,543	116,985	362,675	266,755
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member]
Disaggregation Of Revenue [Line Items]
Revenues		88,568	74,913	252,753	150,540
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member] | Sawlogs [Member]
Disaggregation Of Revenue [Line Items]
Revenues		88,244	72,815	251,198	144,860
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member] | Pulpwood [Member]
Disaggregation Of Revenue [Line Items]
Revenues		119	1,243	815	3,914
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member] | Stumpage [Member]
Disaggregation Of Revenue [Line Items]
Revenues					316
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues		205	855	740	1,450
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member]
Disaggregation Of Revenue [Line Items]
Revenues		40,975	42,072	109,922	116,215
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member] | Sawlogs [Member]
Disaggregation Of Revenue [Line Items]
Revenues		22,191	25,462	65,620	70,606
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member] | Pulpwood [Member]
Disaggregation Of Revenue [Line Items]
Revenues		13,843	13,413	33,167	35,486
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member] | Stumpage [Member]
Disaggregation Of Revenue [Line Items]
Revenues		2,275	770	3,310	2,416
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues		2,666	2,427	7,825	7,707
Wood Products [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues		187,760	218,291	814,729	489,507
Wood Products [Member] | Operating Segments [Member] | Lumber [Member]
Disaggregation Of Revenue [Line Items]
Revenues		141,255	185,558	679,417	400,290
Wood Products [Member] | Operating Segments [Member] | Residuals and Panels [Member]
Disaggregation Of Revenue [Line Items]
Revenues		46,505	32,733	135,312	89,217
Real Estate Segment [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues		13,497	18,151	49,808	42,225
Real Estate Segment [Member] | Operating Segments [Member] | Rural Real Estate [Member]
Disaggregation Of Revenue [Line Items]
Revenues		6,939	13,284	28,469	30,455
Real Estate Segment [Member] | Operating Segments [Member] | Development Real Estate [Member]
Disaggregation Of Revenue [Line Items]
Revenues		4,260	2,157	14,087	6,121
Real Estate Segment [Member] | Operating Segments [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues		$ 2,298	$ 2,710	$ 7,252	$ 5,649

[1] Intersegment revenues represent logs sold by our Timberlands segment to our Wood Products segment.