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Transactions With Related Parties - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Related Party Transaction [Line Items]
Carrying amount of LTP's assets	$ 3.4		$ 3.4		$ 2.7
Carrying amount of LTP's liabilities	$ 3.4		$ 3.4		$ 2.7
Boise Cascade Co-Owner of LTP
Related Party Transaction [Line Items]
Variable interest entity, ownership percentage	50.00%		50.00%
Boise Cascade Co-Owner of LTP \| Fiber
Related Party Transaction [Line Items]
Revenue from related parties	$ 21.4	$ 22.6	$ 41.4	$ 43.0
Fiber costs from related parties	21.4	22.6	41.4	43.0
Boise Cascade Co-Owner of LTP \| Wood Products, Including Chips and Logs
Related Party Transaction [Line Items]
Fiber costs from related parties	$ 4.4	$ 4.7	$ 8.8	$ 8.7
Packaging Corporation of America
Related Party Transaction [Line Items]
Variable interest entity, ownership percentage	50.00%		50.00%