Pension Information - Components of Net Periodic Pension Benefit (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Compensation And Retirement Disclosure [Abstract]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	125	171	375	509
Expected return on plan assets	(273)	(283)	(819)	(844)
Other components	143	426	429	946
Net periodic pension benefit	$ (5)	$ 314	$ (15)	$ 611

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Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of net periodic benefit cost (credit) for defined benefit plan.

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Amount of defined benefit plan cost (credit), classified as other.

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Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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