Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 65	$ 64	$ 98
Interest cost	119	111	122
Expected return on plan assets	(17)	(8)	(7)
Amortization of prior service cost	76	18	19
Amortization of net transition obligation	(1)	(1)	(1)
Amortization of plan loss	28	22	219
Recognized actuarial net loss	14	7	8
Curtailments	160	0	0
Net periodic pension benefit cost	$ 444	$ 213	$ 458