Property, Plant and Equipment (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended			23 Months Ended
	Feb. 28, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Depreciation expense		$ 30,600,000	$ 25,200,000	$ 23,900,000
Pre-tax gain on sale of facility				9,176,000
Total cash proceeds received after working capital adjustments, closing costs and other expenses			1,000,000	$ 58,793,000
Roseburg Forest Products Co [Member] | Deltic MDF Facility [Member]
Property Plant And Equipment [Line Items]
Total sale price	$ 92,000,000.0
Cash sale price	63,000,000.0
Assumption sale price of revenue bonds	29,000,000.0
Pre-tax gain on sale of facility	$ 9,200,000
Total cash proceeds received after working capital adjustments, closing costs and other expenses			$ 1,000,000.0		$ 59,800,000
Ola, Arkansas Sawmill [Member]
Property Plant And Equipment [Line Items]
Business interruption recoveries		$ 0