Employee Benefit Plans - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Retirement benefits based on years of service and compensation			5 years
Benefit payments from Restoration Plan			$ 19,000
Defined benefit plan, expected additional contribution during remainder of the year	$ 19,000		19,000
Actuarial (gain) loss	$ (494,000)	$ (531,000)	(988,000)	$ (1,062,000)
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial (gain) loss			11,000,000
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Actuarial (gain) loss			$ 13,000,000