Employee Benefit Plans - Schedule of Net Periodic Benefit Cost (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Compensation And Retirement Disclosure [Abstract]
Benefit cost, Interest cost	$ 438	$ 435	$ 877	$ 870
Benefit cost, Expected return on plan assets	(560)	(551)	(1,120)	(1,101)
Benefit cost, Recognized actuarial loss	329	580	658	1,159
Settlement	285	144	285	423
Net periodic benefit cost	$ 492	$ 608	$ 700	$ 1,351