Transactions With Related Parties - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Carrying amount of LTP's assets	$ 7,235.8	$ 6,569.7	$ 6,197.5
Boise Cascade Co-Owner of LTP
Related Party Transaction [Line Items]
Variable interest entity, ownership percentage	50.00%
Boise Cascade Co-Owner of LTP \| Fiber
Related Party Transaction [Line Items]
Revenue from related parties	$ 81.7	83.1	86.4
Fiber costs from related parties	81.7	83.1	86.4
Boise Cascade Co-Owner of LTP \| Wood Products, Including Chips and Logs
Related Party Transaction [Line Items]
Fiber costs from related parties	$ 16.8	16.8	$ 16.6
Packaging Corporation of America
Related Party Transaction [Line Items]
Variable interest entity, ownership percentage	50.00%
Variable Interest Entity
Related Party Transaction [Line Items]
Carrying amount of LTP's assets	$ 3.9	2.7
Carrying amount of LTP's liabilities	$ 3.9	$ 2.7

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

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Amount included in cost of sales related to transactions with related parties incurred and recorded in the statement of operations for the period.

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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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