Pension and Employee Benefit Plans - Components of Pension and Employee Benefit Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]
Service cost	$ 233	$ 204	$ 126
Interest cost	1,412	1,428	676
Expected return on plan assets	(2,009)	(1,950)	(871)
Net amortization and deferral	258	177	370
Net periodic benefit cost	$ (106)	$ (141)	$ 301