Components of Net Unrecognized Benefits Costs (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Net Unrecognized Benefits Costs Of Accumulated Other Comprehensive Income [Line Items]
Included in accumulated other comprehensive income (loss), Beginning Balance	$ 14,879	$ 11,239	$ 10,618
Additions during the year	(3,969)	(649)	443
Reclassifications due to recognition as net periodic pension cost	(1,255)	(1,194)	(1,159)
Increase (decrease) related to change in discount rate assumption	(4,099)	5,483	1,337
Included in accumulated other comprehensive income (loss), Ending Balance	5,539	14,879	11,239
Excess if distributions over reduction in projected benefit obligations	254
Loss recognized due to settlement	(271)
Applicable tax effect	(2,211)
Included in accumulated other comprehensive income (loss) net of tax effect at December 31, 2013	3,328
Amount expected to be recognized as part of net periodic pension cost in the next fiscal year	$ (220)