Acquisition - Narrative (Details) - Genoptix - USD ($) $ in Thousands		1 Months Ended	3 Months Ended	9 Months Ended
	Dec. 10, 2018	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2019
Business Acquisition [Line Items]
Payment for business acquisition	$ 127,000
Payment for working capital adjustments	$ 2,000		$ 2,400
Shares of common stock issued as consideration (in shares)	1,000,000
Payment for working capital adjustments, cash portion		$ 400
Identifiable intangible assets	$ 71,792			$ 68,329
Accounts receivable acquired				16,600
Accounts receivable, fair value adjustment				$ 1,500
Customer Relationships
Business Acquisition [Line Items]
Identifiable intangible assets	54,200
Trade Name
Business Acquisition [Line Items]
Identifiable intangible assets	700
Trademarks
Business Acquisition [Line Items]
Identifiable intangible assets	$ 13,400
Common Stock
Business Acquisition [Line Items]
Shares of common stock issued as consideration (in shares)	1,000,000.0