Leases - Narrative (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Operating lease right-of-use asset	$ 14,924		$ 0
Operating lease liability	14,807		$ 0
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease right-of-use asset	14,900	$ 15,900
Operating lease liability	$ 14,800	$ 15,900