Commitments and Contingencies - Additional Information (Details) (USD $) In Millions, unless otherwise specified	2 Months Ended	12 Months Ended
	Oct. 31, 2010	Dec. 31, 2014 acre		Dec. 31, 2013	Dec. 31, 2012
Schedule Of Commitments And Contingencies [Line Items]
Capital commitments		$ 94.7		$ 151.4
Area leased under timberland cutting rights (acres)		88,000
Average lease renewal term		6 years
Total lease expense		85.6		56.0	49.4
Capital lease obligations		23.9		24.9
Interest paid, capital lease obligations		1.6		1.7	1.7
Purchases during period under purchase agreements		265.9		61.7	27.7
Environmental remediation expense to date		3.2
Environmental reserve		35.4
Environmental liabilities and asset retirement obligations		7.1		7.8
Number of other U.S. and Canadian containerboard producers	PCA and eight other U.S. and Canadian containerboard producers were named as defendants
Number of lawsuits filed by the plaintiffs	5
Class action lawsuit settlement		17.6	[1]	0	0
Asset Retirement Obligation
Schedule Of Commitments And Contingencies [Line Items]
Environmental reserve		26.9
Environmental Contingencies
Schedule Of Commitments And Contingencies [Line Items]
Environmental reserve		8.5
Other Long-Term Liabilities
Schedule Of Commitments And Contingencies [Line Items]
Environmental reserve		$ 28.3
Minimum
Schedule Of Commitments And Contingencies [Line Items]
Remaining lease term		1 year
Purchase commitments term, years		1 year
Maximum
Schedule Of Commitments And Contingencies [Line Items]
Remaining lease term		15 years
Purchase commitments term, years		20 years

[1] Includes $17.6 million of costs for the settlement of the Kleen Products LLC v Packaging Corp. of America et al class action lawsuit. See Note 20, Commitments, Guarantees, Indemnifications, and Legal Proceedings, for more information.