Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended									3 Months Ended			3 Months Ended			3 Months Ended
	Mar. 31, 2012 LegalMatter	Dec. 31, 2011 LegalMatter	Dec. 31, 2010 Minimum LegalMatter	Dec. 31, 2010 Maximum LegalMatter	Mar. 31, 2012 Claims that Specify Amount of Damages Sought LegalMatter	Mar. 31, 2012 Claims that Cite Jurisdictional Amounts LegalMatter	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements LegalMatter	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Minimum LegalMatter	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Maximum LegalMatter	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Legal Claim 1 LegalMatter	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Legal Claim 1 Compensatory	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Legal Claim 1 Punitive	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Legal Claim 2 LegalMatter	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Legal Claim 2 Compensatory	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Legal Claim 2 Punitive	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Legal Claim 3 LegalMatter	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Legal Claim 3 Compensatory	Mar. 31, 2012 Claims that Specify Amount of Damages Sought not Based on Jurisdictional Requirements Legal Claim 3 Punitive	Mar. 31, 2012 Superfund Sites Proceedings LegalMatter	Mar. 31, 2012 PCB Contamination Proceedings	Mar. 31, 2010 PCB Contamination Proceedings
Commitments and Contingencies Disclosure [Line Items]
Number of pending claims	260	242			69	188	3			1			1			1			1
Percentage of pending claims							2.00%
Estimated total cleanup costs, cost sharing percentage																			2.00%
Loss contingency, minimum possible loss																			$ 17.0		$ 1.0
Loss contingency, maximum possible loss																			24.0		2.6
PCB contamination of the building, liability recording during the period																					1.0
Estimated total cleanup costs, accrual	0.3
Estimated total cleanup costs, insurance receivable																			0.3
Remediation and monitoring costs incurred since inception related to the PCB soil contamination																				2.5
Damages sought											20	20		65	60		1	1
Number of defendants			1	833				10	109
Description of named defendants	Cases involving us typically name 50-300 defendants
Number of claims dismissed	31	120
Number of claims settled	6	8
Claims settlements amount	2.1	8.1
Cost Sharing Agreement, Expiration Period	4 years
Cost Sharing Agreement, expiration date	Jan. 25, 2015
Period for recognizing a reserve for future costs	5 years
Asbestos-related liabilities, estimated liability	27.9	28.8
Asbestos-related liabilities, estimated insurance recovery	$ 27.7	$ 28.4