Discontinued operations - Significant Non-Cash Items and Capital Expenditures (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating activities:
Change in fair value of contingent consideration	$ 0	$ 464
Stock-based compensation expense	30,509	101,829
Investing activities:
Purchase of property, plant and equipment	(8,100)	(12,944)
Proceeds from sale of manufacturing facility	0	110,300
Purchase of intangible assets	0	(8,000)
Supplemental cash flow disclosures:
Purchases of property, plant and equipment included in accounts payable and accrued expenses	$ 176	732
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff | 2seventy bio
Operating activities:
Change in fair value of contingent consideration		464
Depreciation and amortization		12,967
Stock-based compensation expense		26,189
Loss on fixed asset disposal		254
Loss on sale of manufacturing facility		1,986
Investing activities:
Purchase of property, plant and equipment		(10,579)
Proceeds from sale of manufacturing facility		110,300
Purchase of intangible assets		(8,000)
Supplemental cash flow disclosures:
Purchases of property, plant and equipment included in accounts payable and accrued expenses		$ 321