Acquisition - Intangible assets acquired (Details) - Triage Business [Member] $ in Thousands	Oct. 06, 2017 USD ($)
Business Acquisition [Line Items]
Fair value of assets acquired	$ 184,900
Purchased technology
Business Acquisition [Line Items]
Amortization period	10 years
Fair value of assets acquired	$ 52,400
Customer relationships
Business Acquisition [Line Items]
Amortization period	7 years
Fair value of assets acquired	$ 115,000
Trademarks
Business Acquisition [Line Items]
Amortization period	10 years
Fair value of assets acquired	$ 17,500