Amounts not yet Reflected in Net Periodic Pension Cost and Included in Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Prior service cost		$ 2,502
Loss	8,652	7,378
Accumulated other comprehensive loss	$ 8,652	$ 9,880

After tax total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s).

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant