Leases - Summary of Components of Lease Costs (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2019
Finance lease costs:
Amortization of right-of-use assets	$ 245	$ 484
Interest on finance lease liabilities	231	454
Operating lease costs	540	1,080
Short-term lease costs	72	134
Variable lease costs	176	328
Total lease costs	$ 1,264	$ 2,480

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- Definition

Amount of interest expense on finance lease liability.

+ References

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- Definition

Amount of amortization expense attributable to right-of-use asset from finance lease.

+ References

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- Definition

Amount of lease cost recognized by lessee for lease contract.

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- Definition

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.

+ References

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Amount of short-term lease cost, excluding expense for lease with term of one month or less.

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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.

+ References

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