Basis of Presentation and Significant Accounting Policies - Adjustments for Adoption (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use assets - operating leases	$ 6,940	$ 8,289
Operating lease liability, current	2,029	2,245
Operating lease liability, long term	$ 5,120	6,044
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use assets - operating leases		8,289
Operating lease liability, current		2,245
Operating lease liability, long term		$ 6,044