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Tax Cuts and Jobs Act of 2017, incomplete accounting, provisional income tax expense (benefit).

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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 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, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Federal corporate tax rate			21.00%	35.00%	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			$ 140.8	298.7	$ 222.1
Gross reserve for unrecognized tax benefits, excluding interest and penalties	4.6	4.8	4.6	4.8	$ 5.2	$ 5.8
Unrecognized tax benefits that would impact of effective tax rate	4.0		4.0
Interest accrued related to unrecognized tax benefits and penalties	1.1	$ 1.1	1.1	$ 1.1
Reasonably possible decrease in unrecognized tax benefits related to state apportionment issues in next 12 months	$ 3.1		$ 3.1
Boise Inc.
Income Taxes [Line Items]
Open tax year			2013
Boise Inc. \| Earliest Tax Year
Income Taxes [Line Items]
Open tax year			2008
Boise Inc. \| Latest Tax Year
Income Taxes [Line Items]
Open tax year			2011
Foreign
Income Taxes [Line Items]
Open tax year			2009
State taxing jurisdiction \| Earliest Tax Year
Income Taxes [Line Items]
Open tax year			2014
State taxing jurisdiction \| Latest Tax Year
Income Taxes [Line Items]
Open tax year			2018
Internal Revenue Service (IRS)
Income Taxes [Line Items]
Income tax examination (description)			A federal examination of the 2013 tax year was concluded in November 2016.
Internal Revenue Service (IRS) \| Earliest Tax Year
Income Taxes [Line Items]
Open tax year			2015
Internal Revenue Service (IRS) \| Latest Tax Year
Income Taxes [Line Items]
Open tax year			2018