Pension and Other Postretirement Benefits - Schedule of Changes in Plan Assets (Detail) In Thousands, unless otherwise specified	12 Months Ended									12 Months Ended
	Dec. 31, 2013 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2013 U.S. Pension Benefits [Member] USD ($)	Dec. 31, 2012 U.S. Pension Benefits [Member] USD ($)	Dec. 31, 2013 Foreign Pension Benefits [Member] USD ($)	Dec. 31, 2012 Foreign Pension Benefits [Member] USD ($)	Dec. 31, 2011 Foreign Pension Benefits [Member] USD ($)	Dec. 31, 2013 Foreign Pension Benefits [Member] GBP (£)	Dec. 31, 2012 Foreign Pension Benefits [Member] GBP (£)	Dec. 31, 2013 Other Postretirement Benefits [Member] USD ($)	Dec. 31, 2012 Other Postretirement Benefits [Member] USD ($)
Change in plan assets:
Fair value of plan assets, Beginning balance			$ 140,218	$ 133,403	$ 41,875	$ 36,436		£ 29,315	£ 25,774	$ 0	$ 0
Actual return on plan assets			26,679	14,240	5,061	3,586				0	0
Foreign currency exchange rate changes			0	0	1,098	1,734				0	0
Corporate contributions	5,000	7,000	5,008	36	1,764	1,786	1,693			597	642
Participant contributions			0	0	0	0				423	428
Gross benefits paid			(7,820)	(7,461)	(1,262)	(1,667)				(1,020)	(1,070)
Fair value of plan assets, Ending balance			$ 164,085	$ 140,218	$ 48,536	$ 41,875	$ 36,436	£ 29,315	£ 25,774	$ 0	$ 0