Pension and Profit Sharing Plans - Net Periodic Pension Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Service cost - benefits earned during the period	$ 0	$ 0	$ 0
Interest cost on projected benefit obligation	665	622	1,131
Expected return on plan assets	(912)	(948)	(1,497)
Amortization of unrecognized net loss	375	222	337
Recognized loss on partial settlement of certain participant balances	267		2,909
Net periodic pension benefit expense (benefit)	$ 395	$ (104)	$ 2,880