Cash, Cash Equivalents and Short-Term Investments - Schedule of Breakdown of the Short-Term Investments (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Less than 12 months
Fair Value	$ 16.9	$ 43.5
Gross Unrealized Losses	(0.2)	(0.2)
More than 12 months
Fair Value	213.9	534.8
Gross Unrealized Losses	(7.0)	(21.1)
Total
Fair Value	230.8	578.3
Gross Unrealized Losses	(7.2)	(21.3)
Corporate notes and obligations
Less than 12 months
Fair Value	1.9	25.1
Gross Unrealized Losses	0.0	(0.1)
More than 12 months
Fair Value	103.8	240.3
Gross Unrealized Losses	(3.3)	(10.2)
Total
Fair Value	105.7	265.4
Gross Unrealized Losses	(3.3)	(10.3)
U.S. Treasury securities
Less than 12 months
Fair Value	9.0	17.8
Gross Unrealized Losses	(0.1)	(0.1)
More than 12 months
Fair Value	65.7	174.0
Gross Unrealized Losses	(2.5)	(6.0)
Total
Fair Value	74.7	191.8
Gross Unrealized Losses	(2.6)	(6.1)
Asset backed securities
Less than 12 months
Fair Value	0.0	0.6
Gross Unrealized Losses	0.0	0.0
More than 12 months
Fair Value	16.0	66.0
Gross Unrealized Losses	(0.3)	(2.3)
Total
Fair Value	16.0	66.6
Gross Unrealized Losses	(0.3)	(2.3)
Municipal securities
Less than 12 months
Fair Value	6.0	0.0
Gross Unrealized Losses	(0.1)	0.0
More than 12 months
Fair Value	23.1	46.1
Gross Unrealized Losses	(0.6)	(2.0)
Total
Fair Value	29.1	46.1
Gross Unrealized Losses	(0.7)	(2.0)
U.S. agency obligations
Less than 12 months
Fair Value	0.0	0.0
Gross Unrealized Losses	0.0	0.0
More than 12 months
Fair Value	3.6	3.5
Gross Unrealized Losses	(0.2)	(0.3)
Total
Fair Value	3.6	3.5
Gross Unrealized Losses	(0.2)	(0.3)
Foreign government obligations
Less than 12 months
Fair Value		0.0
Gross Unrealized Losses		0.0
More than 12 months
Fair Value		3.3
Gross Unrealized Losses		(0.2)
Total
Fair Value		3.3
Gross Unrealized Losses		(0.2)
Supranational securities
Less than 12 months
Fair Value	0.0	0.0
Gross Unrealized Losses	0.0	0.0
More than 12 months
Fair Value	1.7	1.6
Gross Unrealized Losses	(0.1)	(0.1)
Total
Fair Value	1.7	1.6
Gross Unrealized Losses	$ (0.1)	$ (0.1)

Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions

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