Intangible assets and goodwill - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 58,700,000	$ 25,000,000.0	$ 8,600,000
Intangible assets, weighted average useful life	13 years 7 months 6 days
Goodwill, impairment loss	$ 0	0
In-process research and development	$ 29,000,000.0	$ 50,000,000.0