Goodwill and Other Intangible Assets (Details 2) (USD $) In Millions, unless otherwise specified								9 Months Ended			9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Trade names	Dec. 31, 2011 Trade names	Sep. 30, 2012 Trade names Wausau Paper Mills, LLC	Sep. 30, 2012 Customer based intangibles	Dec. 31, 2011 Customer based intangibles	Sep. 30, 2012 Customer based intangibles Wausau Paper Mills, LLC	Sep. 30, 2012 Trade names and trademarks	Dec. 31, 2011 Trade names and trademarks	Sep. 30, 2012 Trade names and trademarks Wausau Paper Mills, LLC	Sep. 30, 2012 Acquired technology	Dec. 31, 2011 Acquired technology
Intangible assets
Amortizable intangible assets, Gross Amount	$ 22.5	$ 20.5				$ 16.0	$ 14.1	$ 2.0	$ 5.5	$ 5.4		$ 1.0	$ 1.0
Amortizable intangible assets, Accumulated Amortization	(9.6)	(8.3)				(5.8)	(5.0)		(3.2)	(2.8)	0.2	(0.6)	(0.5)
Unamortizable intangible assets, Gross Amount			21.2	9.7	11.5
Total, Gross Amount	$ 43.7	$ 30.2
Weighted average useful lives								15 years			8 years