Benefit Plans - Additional Information (Detail) - Defined Benefit Pension Plan [Member] $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) Employee	Jun. 30, 2015 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Matching contribution by the company to the plan			100.00%
Percentage of employees' eligible compensation			6.00%
Company contribution to defined benefit plan recorded as compensation expense | $	$ 0.1	$ 0.3	$ 0.4	$ 0.5
Number of employees covered under defined benefit pension plan			28
Retired Employee [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of employees covered under defined benefit pension plan			2
Deferred Vested Termination [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of employees covered under defined benefit pension plan			4
Survivor [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of employees covered under defined benefit pension plan			1