Revenue Recognition (Summary of Revenues by Major Product) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Revenues		$ 226,302	$ 289,199	$ 623,599	$ 757,329
Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues		261,315	321,679	709,286	851,082
Intersegment Eliminations [Member]
Disaggregation Of Revenue [Line Items]
Revenues	[1]	(35,013)	(32,480)	(85,687)	(93,753)
Timberlands [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues		98,809	111,421	233,848	280,438
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member]
Disaggregation Of Revenue [Line Items]
Revenues		55,729	72,037	122,574	174,931
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member] | Sawlogs [Member]
Disaggregation Of Revenue [Line Items]
Revenues		53,152	69,658	116,118	168,869
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member] | Pulpwood [Member]
Disaggregation Of Revenue [Line Items]
Revenues		1,489	1,575	4,698	4,654
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member] | Stumpage [Member]
Disaggregation Of Revenue [Line Items]
Revenues		3	39	109	175
Timberlands [Member] | Operating Segments [Member] | Northern Region [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues		1,085	765	1,649	1,233
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member]
Disaggregation Of Revenue [Line Items]
Revenues		43,080	39,384	111,274	105,507
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member] | Sawlogs [Member]
Disaggregation Of Revenue [Line Items]
Revenues		24,053	21,974	63,469	61,194
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member] | Pulpwood [Member]
Disaggregation Of Revenue [Line Items]
Revenues		15,754	13,700	38,847	36,138
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member] | Stumpage [Member]
Disaggregation Of Revenue [Line Items]
Revenues		767	653	1,233	2,106
Timberlands [Member] | Operating Segments [Member] | Southern Region [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues		2,506	3,057	7,725	6,069
Wood Products [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues		143,643	199,025	413,979	532,425
Wood Products [Member] | Operating Segments [Member] | Lumber [Member]
Disaggregation Of Revenue [Line Items]
Revenues		108,364	138,281	301,923	367,062
Wood Products [Member] | Operating Segments [Member] | Residuals and Panels [Member]
Disaggregation Of Revenue [Line Items]
Revenues		35,279	60,744	112,056	165,363
Real Estate Segment [Member] | Operating Segments [Member]
Disaggregation Of Revenue [Line Items]
Revenues		18,863	11,233	61,459	38,219
Real Estate Segment [Member] | Operating Segments [Member] | Rural Real Estate [Member]
Disaggregation Of Revenue [Line Items]
Revenues		9,689	8,238	44,223	29,740
Real Estate Segment [Member] | Operating Segments [Member] | Development Real Estate [Member]
Disaggregation Of Revenue [Line Items]
Revenues		7,674	1,287	12,102	4,249
Real Estate Segment [Member] | Operating Segments [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues	[2]	$ 1,500	$ 1,708	$ 5,134	$ 4,230

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

[2] Other Real Estate revenues primarily relate to the Chenal Country Club.