Leases - Lease cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lease Cost [Abstract]
Amortization of ROU assets	$ 525	$ 422	$ 1,512	$ 1,265
Interest on lease liabilities	299	296	900	901
Operating lease cost	8,361	7,233	24,189	23,156
Short-term lease cost	38	97	172	172
Variable lease cost	12	3	37	5
Sublease Income	(23)	(29)	(83)	(84)
Net gain recognized from sale and lease back transaction	0	0	(5,550)	0
Total lease cost	$ 9,212	$ 8,022	$ 21,177	$ 25,415

Amount of interest expense on finance lease liability.

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-Name Accounting Standards Codification
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-Section 50
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- Definition

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

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- Definition

Amount of lease cost recognized by lessee for lease contract.

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No definition available.

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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 gain (loss) on sale and leaseback transaction from transfer of asset accounted for as sale.

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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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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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