Restructuring (Details) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
Aug. 31, 2018 employee	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Restructuring and Related Activities [Abstract]
Number of positions eliminated \| employee	35
Workforce eliminated as a percentage	22.00%
Restructuring charges \| $		$ 2,151	$ 56	$ 2,151	$ 2,541

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Period Type:	duration