Schedule of Additional Information Regarding the Company's Real Estate Operating Leases (Detail) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($)
Lease cost
Operating leases	$ 2,121
Variable leases	2
Total lease cost	2,123
Other information on operating leases
Cash payments included in the measurement of lease liabilities reported in operating cash flows	$ 2,459
Weighted average discount rate	2.97%
Weighted average remaining lease term in years	7 years 2 months 12 days

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Amount of lease cost recognized by lessee for lease contract.

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Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

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Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

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Weighted average discount rate for operating lease calculated at point in time.

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Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

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