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Financial Instruments and Fair Value (Tables)

9 Months Ended

Sep. 30, 2025

Financial Instruments and Fair Value [Abstract]

Summary of Investments

The following tables summarize our short-term and long-term investments (in millions):

			September 30, 2025
			Amortized Cost						Unrealized Gains						Unrealized Losses						Fair Value
U.S. government and agency securities			$	560.0					$	0.6					$	(0.1)					$	560.5
Commercial paper			370.4						0.1						—						370.5
Corporate debt securities			285.2						0.3						(0.1)						285.4
Certificates of deposit and term deposits			102.2						0.1						—						102.3
Total available-for-sale investments			1,317.8						1.1						(0.2)						1,318.7
Marketable equity securities																					98.1
Total short-term and long-term investments			$	1,317.8					$	1.1					$	(0.2)					$	1,416.8

			December 31, 2024
			Amortized Cost						Unrealized Gains						Unrealized Losses						Fair Value
U.S. government and agency securities			$	469.1					$	0.4					$	—					$	469.5
Commercial paper			428.7						0.2						(0.2)						428.7
Corporate debt securities			166.4						0.1						(0.1)						166.4
Certificates of deposit and term deposits			61.8						—						—						61.8
Total available-for-sale investments			1,126.0						0.7						(0.3)						1,126.4
Marketable equity securities																					64.2
Total short-term and long-term investments			$	1,126.0					$	0.7					$	(0.3)					$	1,190.6

Schedule of Unrealized Loss on Investments

The following tables show the gross unrealized losses and the related fair values of our available-for-sale investments that have been in a continuous unrealized loss position (in millions):

			September 30, 2025
			Less Than 12 Months												12 Months or Greater												Total
			Fair Value						Unrealized Losses						Fair Value						Unrealized Losses						Fair Value						Unrealized Losses
U.S. government and agency securities			$	560.5					$	(0.1)					$	—					$	—					$	560.5					$	(0.1)
Commercial paper			370.5						—						—						—						370.5						—
Corporate debt securities			285.4						(0.1)						—						—						285.4						(0.1)
Certificates of deposit and term deposits			102.3						—						—						—						102.3						—
Total available-for-sale investments			$	1,318.7					$	(0.2)					$	—					$	—					$	1,318.7					$	(0.2)

			December 31, 2024
			Less Than 12 Months												12 Months or Greater												Total
			Fair Value						Unrealized Losses						Fair Value						Unrealized Losses						Fair Value						Unrealized Losses
U.S. government and agency securities			$	27.8					$	—					$	—					$	—					$	27.8					$	—
Commercial paper			149.4						(0.2)						—						—						149.4						(0.2)
Corporate debt securities			63.5						(0.1)						—						—						63.5						(0.1)
Certificates of deposit and term deposits			10.9						—						—						—						10.9						—
Total available-for-sale investments			$	251.6					$	(0.3)					$	—					$	—					$	251.6					$	(0.3)

Investments Classified by Contractual Maturity Date

The contractual maturities of our available-for-sale investments were (in millions):

			September 30, 2025						December 31, 2024
Due within one year			$	1,029.6					$	1,126.4
Due within one to three years			289.1						—
Total			$	1,318.7					$	1,126.4

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following table presents the fair value of our financial assets measured at fair value on a recurring basis (in millions):

			September 30, 2025																								December 31, 2024
			Aggregate Fair Value						Quoted Prices in Active Markets For Identical Assets						Significant Other Observable Remaining Inputs						Significant Other Unobservable Remaining Inputs						Aggregate Fair Value						Quoted Prices in Active Markets For Identical Assets						Significant Other Observable Remaining Inputs						Significant Other Unobservable Remaining Inputs
									(Level 1)						(Level 2)						(Level 3)												(Level 1)						(Level 2)						(Level 3)
Cash equivalents:
Money market funds			$	170.5					$	170.5					$	—					$	—					$	296.1					$	296.1					$	—					$	—
Commercial paper			34.0						—						34.0						—						59.7						—						59.7						—
Certificates of deposit and term deposits			4.5						—						4.5						—						—						—						—						—
Total cash equivalents			209.0						170.5						38.5						—						355.8						296.1						59.7						—
Short-term investments:
U.S. government and agency securities			437.1						437.1						—						—						469.5						464.5						5.0						—
Commercial paper			370.5						—						370.5						—						428.7						—						428.7						—
Corporate debt securities			119.7						—						119.7						—						166.4						—						166.4						—
Certificates of deposit and term deposits			102.3						—						102.3						—						61.8						—						61.8						—
Marketable equity securities			98.1						98.1						—						—						64.2						64.2						—						—
Total short-term investments			1,127.7						535.2						592.5						—						1,190.6						528.7						661.9						—
Long-term investments:
U.S. government and agency securities			123.4						113.3						10.1						—						—						—						—						—
Corporate debt securities			165.7						—						165.7						—						—						—						—						—
Total long-term investments			289.1						113.3						175.8						—						—						—						—						—
Total			$	1,625.8					$	819.0					$	806.8					$	—					$	1,546.4					$	824.8					$	721.6					$	—

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Tabular disclosure of fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3).

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