Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Operating lease cost	$ 696	$ 729	$ 1,350	$ 1,453
Finance lease cost:
Amortization of leased assets	546	679	1,164	1,225
Interest on lease liabilities	140	177	288	240
Variable lease cost	669	1,055	1,596	2,121
Sublease income	(8)	(22)	(32)	(73)
Total net lease cost	2,043	2,618	4,366	4,966
Short-term lease cost	$ 100	$ 200	$ 200	$ 400

Amount of interest expense on finance lease liability.

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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of amortization expense attributable to right-of-use asset from finance lease.

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Amount of lease cost recognized by lessee for lease contract.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of operating lease expense. Excludes sublease income.

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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 sublease income excluding finance and operating lease expense.

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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.

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