Pension and Other Postretirement Benefits - Summary of Accumulated Other Comprehensive Loss, Changes in these Amounts and Expected Amortization of these Amounts as Components of Net Periodic Benefit Cost (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Pension Benefits [Member]
Pension And Other Employee Benefit Plans [Line Items]
Net actuarial loss, beginning of year	$ 68,463
Net actuarial loss	79,370
Amortization cost	(5,974)
Net prior service credit	(223)
Liability loss	21,785
Total	79,147
Asset gain	(5,337)
Currency impact	433
Net actuarial loss, end of year	79,370
Prior service credit, beginning of year	(281)
Amortization credit	55
Currency impact	3
Prior service credit, end of year	(223)
Amortization of prior service credit	(54)
Amortization of net loss	6,507
Total	6,453
Other Benefits [Member]
Pension And Other Employee Benefit Plans [Line Items]
Net actuarial loss, beginning of year	11,846
Net actuarial loss	13,116
Amortization cost	(842)
Net prior service credit	(388)
Liability loss	1,950
Total	12,728
Currency impact	162
Net actuarial loss, end of year	13,116
Prior service credit, beginning of year	(488)
Amortization credit	111
Currency impact	(11)
Prior service credit, end of year	(388)
Amortization of prior service credit	(111)
Amortization of net loss	937
Total	$ 826