Litigation - Summary of Activity in Asbestos Insurance Recoveries (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Loss Contingencies [Line Items]
Insurance receivable - asbestos, end of the year	$ 140,651
Asbestos Claims [Member]
Loss Contingencies [Line Items]
Insurance receivable - asbestos, beginning of the year	110,741	118,115
Settlement and defense costs paid by insurance carriers	(17,159)	(23,714)
Changes in estimated coverage	47,069	16,340
Insurance receivable - asbestos, end of the year	$ 140,651	$ 110,741