Amounts Reclassified from Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications	$ 1,250	$ 1,204	$ 8,074	$ 2,407
Amounts Reclassification from Accumulated Other Comprehensive Income | Amortization of defined benefit pension items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Actuarial losses	2,017		4,446
Special termination benefits			2,214
Tax expense	(767)		(2,529)
Total reclassifications	$ 1,250		$ 4,131