Summary of Significant Accounting Policies - New Accounting Principles (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
New Accounting Principles
Right-of-use assets	$ 2,300
Operating lease liabilities	$ 2,285
Accounting Standards Update 2016-02 | Adjustment
New Accounting Principles
Right-of-use assets		$ 2,300
Operating lease liabilities		$ 2,300