Pension and Other Postretirement Benefits - Summary of Changes in the Fair Value of the Level 3 Plan Assets for U.S. and Foreign Pension Plans (Detail) In Thousands, unless otherwise specified			12 Months Ended			12 Months Ended								12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2014 Significant Unobservable Inputs (Level 3) [Member] USD ($)	Dec. 31, 2014 U.S. Pension Benefits [Member] USD ($)	Dec. 31, 2013 U.S. Pension Benefits [Member] USD ($)	Dec. 31, 2013 U.S. Pension Benefits [Member] Significant Unobservable Inputs (Level 3) [Member] USD ($)	Dec. 31, 2014 U.S. Pension Benefits [Member] Hedge and Absolute Return Funds [Member] Significant Unobservable Inputs (Level 3) [Member] USD ($)	Dec. 31, 2013 U.S. Pension Benefits [Member] Hedge and Absolute Return Funds [Member] Significant Unobservable Inputs (Level 3) [Member] USD ($)	Dec. 31, 2014 U.S. Pension Benefits [Member] Managed Funds [Member] Significant Unobservable Inputs (Level 3) [Member] USD ($)	Dec. 31, 2013 U.S. Pension Benefits [Member] Managed Funds [Member] Significant Unobservable Inputs (Level 3) [Member] USD ($)	Dec. 31, 2014 Foreign Pension Benefits [Member] USD ($)	Dec. 31, 2013 Foreign Pension Benefits [Member] USD ($)	Dec. 31, 2014 Foreign Pension Benefits [Member] GBP (£)	Dec. 31, 2013 Foreign Pension Benefits [Member] GBP (£)	Dec. 31, 2014 Foreign Pension Benefits [Member] Significant Unobservable Inputs (Level 3) [Member] USD ($)	Dec. 31, 2013 Foreign Pension Benefits [Member] Significant Unobservable Inputs (Level 3) [Member] USD ($)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, Beginning balance	$ 157,048	$ 42,194	$ 164,085	$ 140,218	$ 40,822	$ 8,389	$ 6,490	$ 32,433	$ 30,064	$ 48,536	$ 41,875	£ 32,437	£ 29,315	$ 11,041	$ 9,031
Acquisitions							2,225		0						1,100
Withdrawals						(200)	(1,320)	(2,550)	(2,070)					(181)	0
Realized gains						66	563	821	451					0	0
Change in net unrealized gains			29,023	(20,806)		337	431	2,898	3,988	13,993	(823)			615	644
Other, primarily impact from changes in foreign currency exchange rates			0	0		0	0	0	0	(3,144)	1,098			(676)	266
Fair value of plan assets, Ending balance	$ 157,048	$ 42,194	$ 157,048	$ 164,085	$ 40,822	$ 8,592	$ 8,389	$ 33,602	$ 32,433	$ 50,533	$ 48,536	£ 32,437	£ 29,315	$ 10,799	$ 11,041