Financial Instruments and Fair Value - Investments (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,382.8	$ 1,327.3
Unrealized Gains	0.2	1.5
Unrealized Losses	(1.7)	(0.1)
Fair Value	1,381.3	1,328.7
Marketable equity securities	29.5	98.2
Fair Value	1,410.8	1,426.9
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less Than 12 Months, Fair Value	1,381.3	1,328.7
Less Than 12 Months, Unrealized Losses	(1.7)	(0.1)
12 Months or Greater, Fair Value	0.0	0.0
12 Months or Greater, Unrealized Losses	0.0	0.0
Total, Fair Value	1,381.3	1,328.7
Total, Unrealized Losses	(1.7)	(0.1)
Available-for-sale Securities, Debt Maturities, Fair Value [Abstract]
Due within one year	1,041.6	989.0
Due within one to three years	339.7	339.7
Fair Value	1,381.3	1,328.7
U.S. government and agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	544.4	513.7
Unrealized Gains	0.2	0.9
Unrealized Losses	(0.5)	0.0
Fair Value	544.1	514.6
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less Than 12 Months, Fair Value	544.1	514.5
Less Than 12 Months, Unrealized Losses	(0.5)	0.0
12 Months or Greater, Fair Value	0.0	0.0
12 Months or Greater, Unrealized Losses	0.0	0.0
Total, Fair Value	544.1	514.5
Total, Unrealized Losses	(0.5)	0.0
Available-for-sale Securities, Debt Maturities, Fair Value [Abstract]
Fair Value	544.1	514.6
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	289.4	354.8
Unrealized Gains	0.0	0.1
Unrealized Losses	(0.1)	0.0
Fair Value	289.3	354.9
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less Than 12 Months, Fair Value	289.3	354.9
Less Than 12 Months, Unrealized Losses	(0.1)	0.0
12 Months or Greater, Fair Value	0.0	0.0
12 Months or Greater, Unrealized Losses	0.0	0.0
Total, Fair Value	289.3	354.9
Total, Unrealized Losses	(0.1)	0.0
Available-for-sale Securities, Debt Maturities, Fair Value [Abstract]
Fair Value	289.3	354.9
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	443.9	368.5
Unrealized Gains	0.0	0.4
Unrealized Losses	(1.0)	(0.1)
Fair Value	442.9	368.8
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less Than 12 Months, Fair Value	442.9	368.9
Less Than 12 Months, Unrealized Losses	(1.0)	(0.1)
12 Months or Greater, Fair Value	0.0	0.0
12 Months or Greater, Unrealized Losses	0.0	0.0
Total, Fair Value	442.9	368.9
Total, Unrealized Losses	(1.0)	(0.1)
Available-for-sale Securities, Debt Maturities, Fair Value [Abstract]
Fair Value	442.9	368.8
Certificates of deposit and term deposits
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	105.1	90.3
Unrealized Gains	0.0	0.1
Unrealized Losses	(0.1)	0.0
Fair Value	105.0	90.4
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less Than 12 Months, Fair Value	105.0	90.4
Less Than 12 Months, Unrealized Losses	(0.1)	0.0
12 Months or Greater, Fair Value	0.0	0.0
12 Months or Greater, Unrealized Losses	0.0	0.0
Total, Fair Value	105.0	90.4
Total, Unrealized Losses	(0.1)	0.0
Available-for-sale Securities, Debt Maturities, Fair Value [Abstract]
Fair Value	$ 105.0	$ 90.4