Income taxes line items.

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Tax Cuts and Jobs Act of 2017, incomplete accounting, reduction of deductions qualified production activities.

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Tax Cuts And Jobs Act Of 2017, incomplete accounting, transition tax, provisional income tax expense.

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Tax Cuts and Jobs Act of 2017 maximum measurement period to finalize accounting of tax.

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Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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A brief description of status of the tax examination, significant findings to date, and the entity's position with respect to the findings.

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The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

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Tax year that remains open to examination under enacted tax laws, in CCYY format.

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Amount of reasonable estimate for income tax expense (benefit) for which accounting for tax effect for remeasurement of deferred tax from change in tax rate is incomplete pursuant to Tax Cuts and Jobs Act.

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Amount of reasonable estimate for income tax expense (benefit) for which accounting for tax effect is incomplete pursuant to Tax Cuts and Jobs Act.

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Amount of unrecognized tax benefits.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Federal corporate tax rate			21.00%	21.00%	35.00%
Maximum measurement period to finalize accounting of tax			1 year
Income tax benefit as result of Tax Act	$ 2.0	$ 122.1
Re-measurement of deferred tax assets and liabilities due to enacted corporate tax rate					$ 128.0
Reduction in domestic manufacturers deductions					5.1
Transition tax due to tax reform					0.8
Cash payments for income taxes			$ 172.7	$ 140.8	298.7
Gross reserve for unrecognized tax benefits, excluding interest and penalties	4.6	$ 4.8	4.8	4.6	$ 4.8	$ 5.2
Unrecognized tax benefits that would impact of effective tax rate			4.2
Interest accrued related to unrecognized tax benefits and penalties	$ 1.1		1.2	$ 1.1
Reasonably possible decrease in unrecognized tax benefits related to state apportionment issues in next 12 months			$ 3.1
Boise Inc.
Income Taxes [Line Items]
Open tax year			2008 2009 2010 2011 2012 2013
Foreign
Income Taxes [Line Items]
Open tax year			2009
State taxing jurisdiction
Income Taxes [Line Items]
Open tax year			2015 2016 2017 2018 2019
Internal Revenue Service (IRS)
Income Taxes [Line Items]
Income tax examination (description)			A federal examination of the 2016 tax year commenced in April 2019.
Open tax year			2016 2017 2018 2019