Litigation - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	0 Months Ended		12 Months Ended
	Sep. 30, 2013	Feb. 24, 2011 Company Defendant	Dec. 31, 2012	Sep. 30, 2014	Feb. 24, 2011 Defendant
Commitments and Contingencies Disclosure [Abstract]
Number of domestic insurance companies, lawsuit filed against		13
Number of defendant insurers in the coverage action					2
Number of domestic defendant insurers in action		8
Number of domestic insurance companies, remain in litigation		2
Reserves for total costs for asbestos liability claims pending or projected			$ 181,022
Percentage attributable to settlement costs for unasserted claims projected to be filed			73.00%
Reserves for asbestos liability claims				141,659
Insurance recoveries receivable			118,115
Increased estimated coverage	$ 16,340