Assets Held for Sale (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Impairment charge of assets no longer used	$ 4.4
Proceeds from sales of assets	0	0.9	9.1	1.2
Property, plant and equipment held for sale [Abstract]
Assets held-for-sale, property, plant and equipment	167.9		167.9		214.3
Assets held for sale acumulated depreciation	(135.4)		(135.4)		(162.4)
Assets Held For Sale Property Plant and Equipment Net	32.5		32.5		51.9
Land Land Improvements And Logging Roads Net of Road Amortization [Member]
Property, plant and equipment held for sale [Abstract]
Assets held-for-sale, property, plant and equipment	10.0		10.0		13.1
Building [Member]
Property, Plant and Equipment [Line Items]
Proceeds from sales of assets			8.5
Property, plant and equipment held for sale [Abstract]
Assets held-for-sale, property, plant and equipment	15.7		15.7		22.9
Machinery and Equipment [Member]
Property, plant and equipment held for sale [Abstract]
Assets held-for-sale, property, plant and equipment	142.2		142.2		178.3
Fair Value, Inputs, Level 2 [Member]
Property, Plant and Equipment [Line Items]
Impairment charge of assets no longer used		$ 2.4		$ 3.6