Leases - Summary of Lease Cost Table (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Leases [Abstract]
Operating lease cost	$ 1,923		$ 3,837
Variable lease cost	102		119
Sublease income	(103)		(207)
Amortization of ROU assets	80		80
Interest on lease liabilities	20		20
Total lease cost	$ 2,022	$ 12,900	$ 3,849	$ 26,700

Amount of interest expense on finance lease liability.

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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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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 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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