Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019
Adoption of New Accounting Standards
Operating lease liability	$ 3,682
Right-of-use assets	$ 3,670
ASU 2016-02 | Adjustment
Adoption of New Accounting Standards
Operating lease liability		$ 3,140
Right-of-use assets		$ 3,140