Litigation (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended				3 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Administrative Consent Order For Contamination Associated with Historic Use of PCBs [Member]	Dec. 31, 2012 Administrative Consent Order For Installation of Groundwater Contamination System [Member]	Dec. 31, 2012 Silica Cases [Member]	Dec. 31, 2012 Asbestos Cases [Member]
Loss Contingencies [Line Items]
Number of pending cases				72	7
Number of cases dismissed-to-date				1,394	32
Number of cases dismissed					22
Aggregate cost of legal defense for pending silica and asbestos cases	$ 0.2
Site Contingency [Line Items]
Location of plant		Canaan, Connecticut	Adams, Massachusetts
Estimated accrued remediation cost		0.4	0.4
Estimated cost of wastewater treatment upgrades, lower range			6
Estimated cost of wastewater treatment upgrades, upper range			$ 8