Employee Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost		$ 0	$ 0
Interest cost		36	87
Expected return on assets		(45)	(104)
Amortization of prior service cost		0	0
Recognized net actuarial loss		25	21
Settlement losses		414	50
Net benefit cost		430	54
Post-Employment Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 36	51	72
Interest cost	142	141	149
Expected return on assets	0	0	0
Amortization of prior service cost	(338)	(338)	(369)
Recognized net actuarial loss	269	278	18
Settlement losses	0	0	0
Net benefit cost	$ 109	$ 132	$ (130)