Segment Information (Summary Of Information By Business Segment) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Segment Revenues		$ 175,244	$ 190,441	$ 163,229	$ 149,681	$ 155,681	$ 174,027	$ 141,495	$ 127,896	$ 678,595	$ 599,099	$ 575,336
Operating income		37,048	$ 43,793	$ 40,773	$ 23,909	25,716	$ 38,994	$ (34,228)	$ 5,072	145,523	35,554	58,907
Interest expense, net										(27,049)	(28,941)	(32,761)
Income before income taxes										118,474	6,613	26,146
Depreciation, depletion and amortization										29,912	34,190	38,105
Bond discount and deferred loan fees										1,480	1,979	1,481
Basis of real estate sold										6,827	8,011	7,012
Assets		953,079				927,681				953,079	927,681	1,016,612
Capital Expenditures	[1]									28,062	19,288	32,732
Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment Revenues										750,011	656,193	629,078
Operating income										194,142	74,009	91,247
Depreciation, depletion and amortization										27,825	31,451	35,673
Assets		824,719				813,707				824,719	813,707	968,733
Capital Expenditures	[1]									25,930	18,913	32,163
Operating Segments [Member] | Resource [Member]
Segment Reporting Information [Line Items]
Segment Revenues										278,199	256,163	263,875
Operating income										106,105	81,918	76,350
Depreciation, depletion and amortization										20,476	24,090	28,807
Capital Expenditures	[1]									15,120	13,311	13,497
Operating Segments [Member] | Wood Products [Member]
Segment Reporting Information [Line Items]
Segment Revenues										441,157	367,426	336,214
Operating income										72,166	24,587	(5,235)
Depreciation, depletion and amortization										7,347	7,357	6,810
Assets		154,479				150,855				154,479	150,855	131,103
Capital Expenditures	[1]									10,723	5,491	18,482
Operating Segments [Member] | Real Estate [Member]
Segment Reporting Information [Line Items]
Segment Revenues										30,655	32,604	28,989
Operating income	[2]									18,576	(29,495)	16,849
Depreciation, depletion and amortization										2	4	56
Basis of real estate sold										7,114	8,518	7,394
Capital Expenditures	[1]									87	111	184
Operating Segments [Member] | Resource and Real Estate [Member]
Segment Reporting Information [Line Items]
Assets	[3]	670,240				662,852				670,240	662,852	837,630
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Segment Revenues	[4]									(71,416)	(57,094)	(53,742)
Operating income										(2,705)	(3,001)	3,283
Basis of real estate sold										(287)	(507)	(382)
Corporate [Member]
Segment Reporting Information [Line Items]
Operating income										(48,619)	(38,455)	(32,340)
Depreciation, depletion and amortization										607	760	951
Assets		$ 128,360				$ 113,974				128,360	113,974	47,879
Capital Expenditures	[1]									$ 2,132	$ 375	$ 569

[1] Excludes the acquisition of timber and timberlands.

[2] In the second quarter of 2016, we sold approximately 172,000 acres of timberlands located in central Idaho for $114 million at a loss of $48.5 million before taxes.

[3] Assets are shown on a combined basis for the Resource and Real Estate segments, as we do not report assets separately to management for these segments.

[4] Intersegment revenues are based on prevailing market prices of logs sold by our Resource segment to the Wood Products segment.