Acquisition of Confluence - Fair value of assets acquired and liabilities assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Aug. 03, 2017
Business Acquisition [Line Items]
Goodwill	$ 18,504
Confluence
Business Acquisition [Line Items]
Cash and cash equivalents		$ 622
Accounts receivable, net		574
Other current assets		89
Property and equipment		268
Other intangible assets		751
IPR&D		6,629
Goodwill		18,504
Total assets acquired		27,437
Accounts payable and accrued expenses		656
Deferred tax liability		2,386
Other liabilities		73
Total liabilities assumed		3,115
Total net assets acquired		$ 24,322