Pension, Profit Sharing, and Other Employee Benefit Plans (Components of Net Unrecognized Benefits Costs (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Profit Sharing and Other Employee Benefit Plans [Abstract]
Included in accumulated other comprehensive income (loss), Beginning Balance	$ 5,539,000	$ 14,879,000	$ 11,239,000
Additions during the year	977,000	(3,969,000)	(649,000)
Reclassifications due to recognition as net periodic pension cost	(251,000)	(1,255,000)	(1,194,000)
Increase (decrease) related to change in discount rate assumption	8,509,000	(4,099,000)	5,483,000
Excess if distributions over reduction in projected benefit obligations		254,000
Loss recognized due to settlement		(271,000)
Included in accumulated other comprehensive income (loss), Ending Balance	14,774,000	5,539,000	14,879,000
Applicable tax effect	(5,873,000)
Included in accumulated other comprehensive income (loss) net of tax effect at December 31, 2014	8,901,000
Amount expected to be recognized as part of net periodic pension cost in the next fiscal year	$ 1,168,000