Segment Information - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Disaggregation of Revenue [Line Items]
Product revenues	$ 3,076,400,000	$ 2,771,900,000	$ 8,811,300,000	$ 8,108,100,000
Depreciation and amortization expense	54,000,000.0	53,200,000	154,100,000	160,700,000
CASGEVY
Disaggregation of Revenue [Line Items]
Product revenues	16,900,000	2,000,000.0	61,500,000	2,000,000.0
JOURNAVX
Disaggregation of Revenue [Line Items]
Product revenues	$ 19,600,000	$ 0	$ 32,900,000	$ 0