Schedule of Amounts Included in Accumulated Other Comprehensive Income Expected To Be Recognized In Net Periodic Benefit Costs (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013
Pension Benefits
Schedule of Pension and Other Postretirement Benefits Recognized in Accumulated Other Comprehensive Income (Loss) [Line Items]
Loss recognition	$ 9,039
Prior service cost (credit) recognition	84
Transition obligation recognition	2
Other Benefits
Schedule of Pension and Other Postretirement Benefits Recognized in Accumulated Other Comprehensive Income (Loss) [Line Items]
Loss recognition	332
Prior service cost (credit) recognition	(335)
Transition obligation recognition	$ 0

Amount included in accumulated other comprehensive income (AOCI) related to transition obligation (asset) expected to be recognized as components of net periodic benefit cost (credit) for the fiscal year that follows the most recent annual statement of financial position.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (s)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanAmortizationOfNetTransitionAssetObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration