Business and Operations - Revision of Previously Issued Financial Statements (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Goodwill	$ 133,408	$ 100,428	$ 0
Intangible assets, net	47,149	39,264
Accumulated other comprehensive loss	(13,521)	(6,716)
Accumulated deficit	$ (372,889)	(317,146)
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Goodwill		101,375
Intangible assets, net		39,658
Accumulated other comprehensive loss		(5,389)
Accumulated deficit		(317,132)
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Goodwill		(947)
Intangible assets, net		(394)
Accumulated other comprehensive loss		(1,327)
Accumulated deficit		$ (14)

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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