Cash, Cash Equivalents and Short-Term Investments - Schedule of Breakdown of the Short-Term Investments (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Less than 12 months
Fair Value	$ 8.0	$ 16.9
Gross Unrealized Losses	(0.1)	(0.2)
More than 12 months
Fair Value	167.4	213.9
Gross Unrealized Losses	(3.4)	(7.0)
Total
Fair Value	175.4	230.8
Gross Unrealized Losses	(3.5)	(7.2)
Corporate notes and obligations
Less than 12 months
Fair Value	1.9	1.9
Gross Unrealized Losses	0.0	0.0
More than 12 months
Fair Value	75.9	103.8
Gross Unrealized Losses	(1.6)	(3.3)
Total
Fair Value	77.8	105.7
Gross Unrealized Losses	(1.6)	(3.3)
U.S. Treasury securities
Less than 12 months
Fair Value	0.0	9.0
Gross Unrealized Losses	0.0	(0.1)
More than 12 months
Fair Value	67.0	65.7
Gross Unrealized Losses	(1.3)	(2.5)
Total
Fair Value	67.0	74.7
Gross Unrealized Losses	(1.3)	(2.6)
Municipal securities
Less than 12 months
Fair Value	6.1	6.0
Gross Unrealized Losses	(0.1)	(0.1)
More than 12 months
Fair Value	14.6	23.1
Gross Unrealized Losses	(0.2)	(0.6)
Total
Fair Value	20.7	29.1
Gross Unrealized Losses	(0.3)	(0.7)
Asset backed securities
Less than 12 months
Fair Value	0.0	0.0
Gross Unrealized Losses	0.0	0.0
More than 12 months
Fair Value	6.2	16.0
Gross Unrealized Losses	(0.2)	(0.3)
Total
Fair Value	6.2	16.0
Gross Unrealized Losses	(0.2)	(0.3)
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	3.7	3.6
Gross Unrealized Losses	(0.1)	(0.2)
Total
Fair Value	3.7	3.6
Gross Unrealized Losses	$ (0.1)	(0.2)
Supranational securities
Less than 12 months
Fair Value		0.0
Gross Unrealized Losses		0.0
More than 12 months
Fair Value		1.7
Gross Unrealized Losses		(0.1)
Total
Fair Value		1.7
Gross Unrealized Losses		$ (0.1)

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

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