Marketable Securities and Equity Investments - Schedule of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2025	Jun. 30, 2025	Dec. 31, 2024
Cash equivalents
Amortized Cost		$ 1,012.6	$ 1,687.1
Fair Value		1,012.6	1,687.1
Total marketable available-for-sale debt securities
Gross Unrealized Losses		(1.2)
Corporate equity securities
Amortized Cost		60.0	72.1
Gross Unrealized Gains	$ 3.0	0.0
Gross Unrealized Losses	$ (38.5)	(32.1)
Fair Value		27.9	36.6
Amortized Cost		7,048.8	6,680.5
Gross Unrealized Gains		41.0	22.8
Gross Unrealized Losses		(33.3)	(49.1)
Fair Value		7,056.5	6,654.2
Total cash equivalents and marketable securities, Amortized Cost		8,061.4	8,367.6
Total cash equivalents and marketable securities, Gross Unrealized Gains		41.0	22.8
Total cash equivalents and marketable securities, Gross Unrealized Losses		(33.3)	(49.1)
Total cash equivalents and marketable securities, Fair Value		8,069.1	8,341.3
U.S. Treasury securities
Total marketable available-for-sale debt securities
Amortized Cost		1,806.8	1,603.9
Gross Unrealized Gains		11.7	3.6
Gross Unrealized Losses		(0.4)	(5.5)
Fair Value		1,818.1	1,602.0
U.S. government agency securities
Total marketable available-for-sale debt securities
Amortized Cost		194.2	240.5
Gross Unrealized Gains		0.8	0.5
Gross Unrealized Losses		0.0	(0.5)
Fair Value		195.0	240.5
Asset-backed securities
Total marketable available-for-sale debt securities
Amortized Cost		1,391.9	1,239.6
Gross Unrealized Gains		5.7	5.1
Gross Unrealized Losses		(0.3)	(0.5)
Fair Value		1,397.3	1,244.2
Certificates of deposit
Total marketable available-for-sale debt securities
Amortized Cost		24.1	0.0
Gross Unrealized Gains		0.0	0.0
Gross Unrealized Losses		0.0	0.0
Fair Value		24.1	0.0
Corporate debt securities
Total marketable available-for-sale debt securities
Amortized Cost		3,540.8	3,519.4
Gross Unrealized Gains		22.8	10.6
Gross Unrealized Losses		(0.5)	(4.1)
Fair Value		3,563.1	3,525.9
Commercial paper
Total marketable available-for-sale debt securities
Amortized Cost		31.0	5.0
Gross Unrealized Gains		0.0	0.0
Gross Unrealized Losses		0.0	0.0
Fair Value		31.0	5.0
Total marketable available-for-sale debt securities
Total marketable available-for-sale debt securities
Amortized Cost		6,988.8	6,608.4
Gross Unrealized Gains		41.0	19.8
Gross Unrealized Losses		(1.2)	(10.6)
Fair Value		$ 7,028.6	$ 6,617.6