Employee Benefit Plans (Detail) - Estimated Amount that will be Recognized From Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Cost (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Defined Benefit Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial net loss	$ (25)
Net prior service credits	0
Net amount recognized	(25)
Post Retirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial net loss	(278)
Net prior service credits	339
Net amount recognized	$ 61