Segment Information (Details) (USD $)	3 Months Ended				9 Months Ended				10 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Oct. 23, 2013
Segment Reporting Information [Line Items]
Number of reportable segments					3				1
Trade sales	$ 1,518,900,000	[1]	$ 845,400,000		$ 4,418,700,000	[1]	$ 2,400,900,000
Net sales	1,518,940,000		845,440,000		4,418,653,000		2,400,877,000
Operating income (loss)	188,378,000	[1]	142,782,000		529,534,000	[1]	358,979,000
Interest expense, net	(23,111,000)	[1],[2]	(11,850,000)	[3]	(65,311,000)	[1],[2]	(30,333,000)	[3]
Income before taxes	165,267,000	[1]	130,932,000		464,223,000	[1]	328,646,000
DeRidder restructuring	4,270,000	[4]	0		5,690,000	[4]	0
Integration-related and other costs	3,040,000	[5]	0		11,999,000	[5]	0
Class action lawsuit settlement	0		0		17,600,000	[6]	0
Curtailment loss	0		3,132,000	[7]	0		10,908,000	[7]
Acquisition-related costs	0		1,479,000	[8]	0		1,479,000	[8]
Packaging
Segment Reporting Information [Line Items]
Trade sales	1,174,200,000	[1]	845,400,000		3,413,800,000	[1]	2,400,900,000
Operating income (loss)	164,700,000	[1],[9]	154,900,000	[10]	501,800,000	[1],[9]	395,100,000	[10]
DeRidder restructuring	26,000,000				47,800,000
Paper
Segment Reporting Information [Line Items]
Trade sales	312,500,000	[1]			917,000,000	[1]
Operating income (loss)	43,000,000	[1],[11]			104,300,000	[1],[11]
Corporate and Other
Segment Reporting Information [Line Items]
Trade sales	32,200,000	[1]	0		87,900,000	[1]	0
Operating income (loss)	(19,300,000)	[1],[12]	(12,100,000)	[13]	(76,600,000)	[1],[12]	(36,100,000)	[13]
Class action lawsuit settlement					17,600,000	[6]
Intersegment Eliminations
Segment Reporting Information [Line Items]
Intersegment sales	0	[1]	0		0	[1]	0
Intersegment Eliminations | Packaging
Segment Reporting Information [Line Items]
Intersegment sales	1,500,000	[1]	0		4,500,000	[1]	0
Intersegment Eliminations | Paper
Segment Reporting Information [Line Items]
Intersegment sales	0	[1]			0	[1]
Intersegment Eliminations | Corporate and Other
Segment Reporting Information [Line Items]
Intersegment sales	37,000,000	[1]	0		112,800,000	[1]	0
Intersegment Eliminations | Intersegment Eliminations
Segment Reporting Information [Line Items]
Intersegment sales	(38,500,000)	[1]			(117,300,000)	[1]
Operating Segments
Segment Reporting Information [Line Items]
Net sales	1,518,900,000	[1]	845,400,000		4,418,700,000	[1]	2,400,900,000
Operating Segments | Packaging
Segment Reporting Information [Line Items]
Net sales	1,175,700,000	[1]	845,400,000		3,418,300,000	[1]	2,400,900,000
Operating Segments | Paper
Segment Reporting Information [Line Items]
Net sales	312,500,000	[1]			917,000,000	[1]
Operating Segments | Corporate and Other
Segment Reporting Information [Line Items]
Net sales	69,200,000	[1]	0		200,700,000	[1]	0
Operating Segments | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net sales	(38,500,000)	[1]			(117,300,000)	[1]
Other Expense, Net | Paper
Segment Reporting Information [Line Items]
Integration-related and other costs					(400,000)
Boise Inc. | Corporate and Other
Segment Reporting Information [Line Items]
Acquisition-related costs			1,500,000				1,500,000
Boise Inc. | Other Expense, Net | Packaging
Segment Reporting Information [Line Items]
Integration-related and other costs	1,000,000				5,400,000
Boise Inc. | Other Expense, Net | Corporate and Other
Segment Reporting Information [Line Items]
Integration-related and other costs	2,000,000				7,000,000
Pension Plans
Segment Reporting Information [Line Items]
Curtailment loss	0		3,132,000	[14]	0		10,908,000	[14]
Pension Plans | Packaging
Segment Reporting Information [Line Items]
Curtailment loss			3,100,000				10,900,000
Write-Off of Deferred Financing Costs
Segment Reporting Information [Line Items]
Interest expense, net	1,500,000				1,500,000
Acquisition-Related Debt Financing Costs [Member] | Acquisition Financing Expense | Boise Inc.
Segment Reporting Information [Line Items]
Interest expense, net			$ 2,700,000				$ 2,700,000

[1] On October 25, 2013, we acquired Boise. The 2014 results include Boise for the full period.

[2] Includes $1.5 million of expense related to the write-off of deferred financing costs in connection with the debt refinancing discussed in Note 10, Debt.

[3] Includes $2.7 million of acquisition-related costs primarily related to financing the acquisition of Boise.

[4] Costs relate primarily to the conversion of the Number 3 newsprint machine at our DeRidder, Louisiana, mill to produce lightweight linerboard and corrugating medium, and our exit from the newsprint business in September 2014.

[5] The three and nine months ended September 30, 2014, include Boise acquisition integration-related and other costs.

[6] The nine months ended September 30, 2014, 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 18, Commitments, Guarantees, Indemnifications and Legal Proceedings, for more information.

[7] The three and nine months ended September 30, 2013, include $3.1 million and $10.9 million, respectively, of non-cash pension curtailment charges related to pension plan changes in which certain hourly corrugated plant and containerboard mill employees will transition from a defined benefit pension plan to a defined contribution (401k) plan.

[8] The three and nine months ended September 30, 2013, both include $1.5 million of acquisition-related costs, primarily for professional fees related to transaction-advisory services and expenses related to financing the acquisition of Boise.

[9] Includes costs related primarily to the conversion of the Number 3 newsprint machine at our DeRidder, Louisiana, mill to produce lightweight linerboard and corrugating medium, and our exit from the newsprint business in September 2014. The three and nine months ended September 30, 2014, include $26.0 million and $47.8 million, respectively, of restructuring charges, primarily accelerated depreciation. The three and nine months ended September 30, 2014, includes $1.0 million and $5.4 million of Boise acquisition integration-related and other costs recorded in "Other expense, net".

[10] Includes $3.1 million and $10.9 million, for the three and nine months ended September 30, 2013, respectively, of non-cash pension curtailment charges related to pension plan changes in which certain hourly corrugated plant and containerboard mill employees will transition from a defined benefit pension plan to a defined contribution (401k) plan.

[11] Includes $0.4 million of income, net of expenses, for the nine months ended September 30, 2014, of integration related and other costs recorded in "Other expense, net".

[12] Includes $2.0 million and $7.0 million, for the three and nine months ended September 30, 2014, of Boise acquisition integration-related and other costs recorded in "Other expense, net".The nine months ended September 30, 2014, 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 18, Commitments, Guarantees, Indemnifications and Legal Proceedings, for more information. These costs are recorded in "Other expense, net".

[13] Includes $1.5 million of Boise acquisition-related costs primarily for professional fees related to transaction-advisory services.

[14] In June 2013, the United Steelworkers (“USW”) ratified a master labor agreement with PCA under which we froze certain USW-represented corrugated plant employees pension accruals under PCA’s hourly pension plan. Additionally, in September 2013, the USW ratified a master labor agreement with PCA under which we froze certain USW-represented containerboard mill employees pension accruals under PCA’s hourly pension plan. Following the pension freezes, affected USW-represented employees will transition to a defined contribution 401k plan. We recorded a $3.1 million and $10.9 million pre-tax pension curtailment charge related to the unrecognized prior service costs of employees impacted by the pension freezes during the three and nine months ended September 30, 2013, respectively. We also remeasured the hourly pension plan benefit obligation using current fair values of plan assets and current assumptions, resulting in a decrease in the benefit obligation of $21.9 million with a corresponding decrease in accumulated other comprehensive income (loss) of $13.4 million and deferred taxes of $8.5 million.