Variable Interest Entities - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended				12 Months Ended			3 Months Ended		6 Months Ended				3 Months Ended		6 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2013	Apr. 30, 2012	Oct. 31, 2012	Mar. 31, 2005 acre	Oct. 31, 2012 Trading Company [Member]	Oct. 31, 2012 Asset Company [Member]	Oct. 31, 2012 Global Textile [Member]	Apr. 30, 2013 STA Timber [Member]	Apr. 30, 2012 STA Timber [Member]	Apr. 30, 2013 STA Timber [Member]	Apr. 30, 2012 STA Timber [Member]	Oct. 31, 2012 STA Timber [Member]	May 31, 2005 STA Timber [Member] Monetization Notes [Member]	Apr. 30, 2013 Flexible Packaging JV [Member]	Apr. 30, 2012 Flexible Packaging JV [Member]	Apr. 30, 2013 Flexible Packaging JV [Member]	Apr. 30, 2012 Flexible Packaging JV [Member]	Apr. 30, 2006 Timberland holdings [Member] acre	Jan. 31, 2006 Timberland holdings [Member] acre
Debt Instrument [Line Items]
Approximate acres of timberland to be sold under agreement with Plum Creek Timberland						56,000
Approximate value of sale agreement with Plum Creek Timberland						$ 90
Acres of timberland sold under the agreement						35,000														5,700	15,300
Value of timberland sold under the agreement						51.0														9.7	29.3
Purchase notes payable						50.9
Maximum amount of guarantee on purchase notes						52.3
Pre-tax gain resulting from sale under agreement																				9.0	27.4
Senior Secured Notes															5.20%
Maturity date															Aug. 05, 2020
Extended date	Nov. 05, 2020		Nov. 05, 2020
Debt instrument, principal outstanding										43.3		43.3		43.3	43.3
Restricted bank financial instruments under Buyer SPE	50.9		50.9		50.9
Interest income of Buyer SPE	0.6	0.6	1.2	1.2
Interest expense	21.4	23.3	43.0	46.2						0.6	0.6	1.2	1.2
Ownership percentage in Variable Interest Entity							51.00%	49.00%	49.00%
Committed capital contribution			150
Commitment to obtain third party financing			Up to $150 million
Variable interest entities outstanding advances	0.6		0.6
Short term loans payable to NSC	12.0		12.0
Net loss attributable to the noncontrolling interest in the Flexible Packaging JV	$ 2.1	$ (0.2)	$ 3.4	$ 0.9												$ 0.4	$ 2.4	$ 1.1	$ 3.8