Balance Sheet Account Details - Additional Information (Details) - USD ($) $ in Thousands			12 Months Ended
	Oct. 06, 2017	May 16, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization expense			$ 16,100	$ 9,500	$ 10,200
Goodwill			337,028	83,834
Depreciation and amortization			14,600	13,400	12,700
Capitalized Software Costs
Finite-Lived Intangible Assets [Line Items]
Amortization expense			$ 800	$ 500	$ 600
Triage Business
Finite-Lived Intangible Assets [Line Items]
Cash consideration	$ 399,798
Goodwill	$ 245,531
RPS Diagnostics
Finite-Lived Intangible Assets [Line Items]
Cash consideration		$ 13,700
Goodwill		7,600
RPS Diagnostics | Technology-Based Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangibles		$ 6,100