New Accounting Standards - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating right-of-use assets	$ 30,054	$ 35,508
Operating lease liability	29,886	35,470
Accumulated deficit	$ (78,729)	246	$ (50,472)
(Accumulated Deficit) Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit		246
(Accumulated Deficit) Retained Earnings | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit		$ 246