Quarterly Financial Data - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended															12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Quarterly Financial Data [Line Items]
Net sales	$ 1,434.0	[1]	$ 1,518.9	[2]	$ 1,468.4	[3]	$ 1,431.3	[4]	$ 1,264.4	[5]	$ 845.5	[6]	$ 800.2	[7]	$ 755.2	$ 5,852.6		$ 3,665.3		$ 2,843.9
Gross profit	297.0	[1]	320.3	[2]	310.8	[3]	301.4	[4]	259.4	[5]	227.6	[6]	195.3	[7]	185.2	1,229.5		867.5		634.7
Operating Income (Loss)	173.2	[1]	188.4	[2]	180.2	[3]	160.9	[4]	122.9	[5]	142.8	[6]	110.2	[7]	106.0	702.7		481.9	[8]	437.6
Net income	98.5	[1]	104.4	[2]	99.6	[3]	90.1	[4]	228.1	[5]	84.7	[6]	66.2	[7]	62.3	392.6		441.3		160.2
Basic income per common share	$ 1.00	[1]	$ 1.06	[2]	$ 1.01	[3]	$ 0.92	[4]	$ 2.36	[5]	$ 0.88	[6]	$ 0.69	[7]	$ 0.65	$ 3.99		$ 4.57		$ 1.66
Diluted income per common share	$ 1.00	[1]	$ 1.06	[2]	$ 1.01	[3]	$ 0.92	[4]	$ 2.34	[5]	$ 0.87	[6]	$ 0.68	[7]	$ 0.64	$ 3.99		$ 4.52		$ 1.64
Stock price - high	$ 80.14		$ 72.82		$ 72.74		$ 75.10		$ 64.39		$ 61.32		$ 50.78		$ 44.93	$ 80.14		$ 64.39
Stock price - low	$ 57.06		$ 63.11		$ 65.00		$ 61.35		$ 55.66		$ 48.45		$ 42.36		$ 37.86	$ 57.06		$ 37.86
Provision (benefit) for income taxes																221.7		(17.7)		214.5
Interest expense, net																(88.4)	[9]	(58.3)	[10],[8]	(62.9)	[11]
Income before taxes																614.3		423.6	[8]	374.7
Settled Litigation
Quarterly Financial Data [Line Items]
Operating Income (Loss)							(17.6)
Decrease (Increase) in net income							11.2
Decrease (Increase) in net income per diluted share							$ 0.11
DeRidder Restructuring Costs
Quarterly Financial Data [Line Items]
Operating Income (Loss)	(18.0)		(26.0)		(17.8)		(4.0)
Decrease (Increase) in net income	11.7		16.6		11.2		2.6
Decrease (Increase) in net income per diluted share	$ 0.12		$ 0.17		$ 0.12		$ 0.02
Non-Cash Pension Curtailment Charge
Quarterly Financial Data [Line Items]
Operating Income (Loss)											(3.1)		(7.8)
Decrease (Increase) in net income											2.0		5.0
Decrease (Increase) in net income per diluted share											$ 0.02		$ 0.05
Alternative Energy Tax Credits
Quarterly Financial Data [Line Items]
Provision (benefit) for income taxes									(166.0)
Decrease (Increase) in net income per diluted share									$ (1.70)
Boise Inc. | Integration-Related and Other Costs
Quarterly Financial Data [Line Items]
Operating Income (Loss)	(6.4)				(4.9)		(4.1)		(17.4)
Income before taxes			(4.5)
Decrease (Increase) in net income	4.2		2.9		3.0		2.6		11.0
Decrease (Increase) in net income per diluted share	$ 0.04		$ 0.03		$ 0.03		$ 0.03		$ 0.11
Boise Inc. | Nonrecurring Acquisition-Related Costs
Quarterly Financial Data [Line Items]
Operating Income (Loss)									(15.8)		(1.5)
Decrease (Increase) in net income									10.0		1.0
Decrease (Increase) in net income per diluted share									$ 0.10		$ 0.01
Boise Inc. | Acquisition-Related Debt Financing Costs
Quarterly Financial Data [Line Items]
Interest expense, net									(8.9)		(2.7)
Decrease (Increase) in net income									5.6		1.8
Decrease (Increase) in net income per diluted share									$ 0.06		$ 0.02
Boise Inc. | Acquisition Inventory Step-Up
Quarterly Financial Data [Line Items]
Operating Income (Loss)									21.5
Decrease (Increase) in net income									$ 13.6
Decrease (Increase) in net income per diluted share									$ 0.14

[1] Includes $18.0 million of DeRidder restructuring charges ($11.7 million after-tax or $0.12 per diluted share) and $6.4 million of integration-related and other costs ($4.2 million after-tax or $0.04 per diluted share).

[2] Includes $26.0 million of DeRidder restructuring charges ($16.6 million after-tax or $0.17 per diluted share) and $4.5 million of integration-related and other costs ($2.9 million after-tax or $0.03 per diluted share).

[3] Includes $17.8 million of DeRidder restructuring charges ($11.2 million after-tax or $0.12 per diluted share) and $4.9 million of integration-related and other costs ($3.0 million after-tax or $0.03 per diluted share).

[4] Includes $17.6 million of costs accrued for the settlement of the Kleen Products LLC v Packaging Corp. of America et al class action lawsuit ($11.2 million after-tax or $0.11 per diluted share), $4.1 million of integration-related costs ($2.6 million after-tax or $0.03 per diluted share), and $4.0 million of DeRidder restructuring charges ($2.6 million after-tax or $0.02 per diluted share).

[5] Includes Boise's results for the period of October 25, 2013, through December 31, 2013. The quarter also includes $166.0 million of income tax benefits from the reversal of the reserves for unrecognized tax benefits from alternative energy tax credits ($1.70 per diluted share), partially offset by $21.5 million of expense for the acquisition inventory step-up ($13.6 million after-tax or $0.14 per diluted share), $15.8 million of acquisition-related costs ($10.0 million after-tax or $0.10 per diluted share), $8.9 million of acquisition-related financing costs ($5.6 million after-tax or $0.06 per diluted share), and $17.4 million of integration-related and other costs ($11.0 million after-tax or $0.11 per diluted share).

[6] Includes a $3.1 million non-cash pension curtailment charge ($2.0 million after-tax or $0.02 per diluted share), $1.5 million of acquisition-related costs ($1.0 million after-tax or $0.01 per diluted share), and $2.7 million of acquisition-related financing costs ($1.8 million after-tax or $0.02 per diluted share).

[7] Includes a $7.8 million non-cash pension curtailment charge ($5.0 million after-tax or $0.05 per diluted share).

[8] On October 25, 2013, we acquired Boise Inc. (Boise). Our financial results include Boise subsequent to acquisition.

[9] 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.

[10] Includes $10.5 million of expenses for financing the acquisition and $1.1 million of expense for the write-off of deferred financing costs.

[11] Includes $24.8 million of debt refinancing charges, including a $21.3 million redemption premium, a $3.4 million charge to settle the treasury lock prior to its maturity, and $0.1 million of other items.