Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liabilities	$ 1,258
Operating lease right-of-use assets	$ 1,258
ASU 2016-02 | Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liabilities		$ 1,482
Operating lease right-of-use assets		$ 1,482