Restructuring - Summary of Restructuring Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 1,907	$ 10,171	$ 7,755	$ 15,758
Restructuring activities prior years [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	1,244	1,164	2,718	1,334
Restructuring activities prior years [Member] | Employee Separation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	54	295	299	(1,516)
Restructuring activities prior years [Member] | Other exit costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	167	869	1,309	4,242
Restructuring activities prior years [Member] | Asset Impairments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	1,023		1,110	147
Restructuring activities prior years [Member] | Postretirement benefit curtailment gain [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring				(1,539)
Restructuring activities 2012 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	349	9,007	3,102	14,263
Restructuring activities 2012 [Member] | Employee Separation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	108	8,797	2,724	14,053
Restructuring activities 2012 [Member] | Other exit costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	241	210	378	210
Restructuring activities 2012 [Member] | Asset Impairments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring