Acquisitions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			0 Months Ended	3 Months Ended	9 Months Ended					0 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Jan. 31, 2013 Southworth Company	Sep. 30, 2013 Southworth Company	Sep. 30, 2013 Southworth Company	Sep. 30, 2013 Southworth Company Trade names and trademarks	Jan. 31, 2013 Southworth Company Trade names and trademarks	Sep. 30, 2013 Southworth Company Customer based intangibles	Jan. 31, 2013 Southworth Company Customer based intangibles	Jan. 31, 2012 Wausau Paper Mills, LLC	Sep. 30, 2012 Wausau Paper Mills, LLC	Sep. 30, 2012 Wausau Paper Mills, LLC
Acquisitions
Cash payment			$ 5.2	$ 14.1		$ 7.0							$ 21.0
Period of finished goods inventory purchased						1 month							1 month
Acquisition-related integration costs	0.4	0.3	0.6	4.7			0.2	0.4						0.3	4.7
Non amortizable intangible assets									5.0	5.0
Amortizable intangible assets											0.6	0.6
Finished goods inventory	63.8		63.8		66.3	1.8
Property, plant and equipment						0.2
Recognized liability						0.6
Expected acquisition-related integration costs						$ 0.6