Leases - Components of Net Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Finance leases:
Amortization of right-of-use assets	$ 387	$ 481	$ 771	$ 978
Interest on lease liabilities	56	65	113	132
Operating lease cost	1,342	1,289	2,647	2,579
Short-term lease cost	110	111	229	220
Variable lease cost	311	332	618	679
Sublease income	(77)	(63)	(153)	(162)
Net lease cost	$ 2,129	$ 2,215	$ 4,225	$ 4,426

Finance lease.

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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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- Definition

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

+ References

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- Definition

Amount of sublease income excluding finance and operating lease expense.

+ References

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- Definition

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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