Commitments & Contingencies - Commitments for Minimum Lease Payments Under Non Cancelable Operating Leases (Detail)	Dec. 31, 2018 USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019	$ 10,184,000
2020	9,345,000
2021	8,193,000
2022	7,750,000
2023	7,250,000
Thereafter	17,832,000
Minimum rental payments under operating leases	60,554,000
Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019	163,000
2020	117,000
2021	116,000
2022	113,000
2023	3,000
Thereafter	0
Minimum rental payments under capital leases	$ 512,000

Amount of minimum lease payments for capital leases.

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-SubTopic 30
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Amount of minimum lease payments for capital leases due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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