Fair value of financial instruments and marketable securities - Narrative (Details)	1 Months Ended				3 Months Ended		6 Months Ended
	Aug. 31, 2021 USD ($)	Feb. 28, 2021 USD ($) fund $ / shares	Jan. 31, 2020 USD ($) $ / shares	May 31, 2019 USD ($) $ / shares	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2019 USD ($)	Aug. 31, 2015 USD ($)
Financial assets and liabilities measured at fair value on recurring basis
Write downs of available for sale debt securities					$ 0		$ 0
Realized gain (loss) from sale of marketable securities					(300,000)	$ 0.0	(400,000)	$ 700,000
Increase in allowance for credit losses					0	0	0	0
Purchase of equity investments								100,000
Unrealized gain (loss) on ClearPoint Equity Investment							2,369,000	4,110,000
Purchase of convertible note							40,429,000	192,931,000
Unrealized gain (loss) on convertible note							1,995,000	4,326,000
Purchase of marketable securities - equity investments	$ 10,000,000.0							200,000,000
Redemption of marketable securities- equity investments							3,630,000
Transfers of assets measured between Level 1, Level 2, and Level 3					0		0		$ 0
Operating Expenses					257,888,000	215,169,000	493,144,000	431,258,000
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Asset					15,200,000	(700,000)	26,900,000	(800,000)
3.00% Convertible senior notes due 2022 | Convertible debt
Financial assets and liabilities measured at fair value on recurring basis
Principal					150,000,000		150,000,000		150,000,000		$ 150,000,000.0
Interest rate ( as a percent )											3.00%
Fair value of convertible notes					150,600,000		150,600,000		158,300,000
1.50% Convertible senior notes due 2026 | Convertible debt
Financial assets and liabilities measured at fair value on recurring basis
Principal					$ 287,500,000		$ 287,500,000		287,500,000	$ 287,500,000
Interest rate ( as a percent )					1.50%		1.50%			1.50%
Fair value of convertible notes					$ 300,400,000		$ 300,400,000		305,300,000
Recurring basis
Financial assets and liabilities measured at fair value on recurring basis
Fair value of convertible debt					22,966,000		22,966,000		20,971,000
ClearPoint equity investment
Financial assets and liabilities measured at fair value on recurring basis
Purchase of equity investments		$ 100,000		$ 4,000,000.0
Share price (in USD per share) | $ / shares		$ 23.50		$ 3.10
Unrealized gain (loss) on ClearPoint Equity Investment					3,400,000	(2,700,000)	2,400,000	4,100,000
Marketable securities - equity investments					16,900,000		16,900,000		14,500,000
ClearPoint convertible debt
Financial assets and liabilities measured at fair value on recurring basis
Purchase of convertible debt investment			$ 10,000,000.0
Conversion price - convertible note | $ / shares			$ 6.00
Term of convertible note			5 years
Unrealized gain (loss) on convertible note					3,500,000	(3,500,000)	2,000,000.0	4,300,000
Fair value of convertible debt					23,000,000.0		23,000,000.0		$ 21,000,000.0
Mutual Funds
Financial assets and liabilities measured at fair value on recurring basis
Purchase of marketable securities - equity investments		$ 200,000,000.0
Number of mutual funds invested in | fund		2
Redemption of marketable securities- equity investments					1,200,000	0	3,600,000	0
Unrealized gain on marketable securities - equity investments						1,000,000.0		700,000
Unrealized loss on marketable securities - equity investments					4,900,000		11,400,000
Unrealized foreign currency transaction gain (loss), net					$ (300,000)	$ 0	$ 400,000	$ 0