Property, Plant and Equipment (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended			28 Months Ended
	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2023
Property Plant And Equipment [Line Items]
Depreciation expense		$ 44,600,000	$ 37,600,000	$ 30,600,000
Ola, Arkansas Sawmill [Member]
Property Plant And Equipment [Line Items]
Deductible amount of property damage and business interruption losses	$ 2,000,000	2,000,000
Proceeds from insurance of claim received		39,400,000	34,100,000	2,900,000	$ 89,400,000
Insurance recoveries to be received		1,600,000
Business interruption recoveries		36,400,000	26,200,000	0
Property damage recoveries		1,400,000	8,800,000	15,000,000
Net of disposal costs and fixed asset write-offs		0	900,000	$ 12,100,000
Waldo Arkansas Sawmill [Member]
Property Plant And Equipment [Line Items]
Expected expansion and modernization cost		131,000,000
Project expansion and modernization cost		74,200,000	12,200,000
Additional depreciation expense		$ 11,900,000	$ 7,000,000