Marketable Securities and Equity Investments - Schedule of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Cash equivalents
Amortized Cost	$ 1,411.0	$ 1,687.1
Fair Value	1,411.0	1,687.1
Total marketable available-for-sale debt securities
Gross Unrealized Losses	(2.2)
Corporate equity securities
Amortized Cost	60.0	72.1
Gross Unrealized Gains	0.0	3.0
Gross Unrealized Losses	(38.4)	(38.5)
Fair Value	21.6	36.6
Amortized Cost	6,691.1	6,680.5
Gross Unrealized Gains	32.5	22.8
Gross Unrealized Losses	(40.6)	(49.1)
Fair Value	6,683.0	6,654.2
Total cash equivalents and marketable securities, Amortized Cost	8,102.1	8,367.6
Total cash equivalents and marketable securities, Gross Unrealized Gains	32.5	22.8
Total cash equivalents and marketable securities, Gross Unrealized Losses	(40.6)	(49.1)
Total cash equivalents and marketable securities, Fair Value	8,094.0	8,341.3
U.S. Treasury securities
Total marketable available-for-sale debt securities
Amortized Cost	1,602.7	1,603.9
Gross Unrealized Gains	8.5	3.6
Gross Unrealized Losses	(0.8)	(5.5)
Fair Value	1,610.4	1,602.0
U.S. government agency securities
Total marketable available-for-sale debt securities
Amortized Cost	217.6	240.5
Gross Unrealized Gains	0.8	0.5
Gross Unrealized Losses	(0.1)	(0.5)
Fair Value	218.3	240.5
Asset-backed securities
Total marketable available-for-sale debt securities
Amortized Cost	1,251.3	1,239.6
Gross Unrealized Gains	4.9	5.1
Gross Unrealized Losses	(0.5)	(0.5)
Fair Value	1,255.7	1,244.2
Certificates of deposit
Total marketable available-for-sale debt securities
Amortized Cost	4.0	0.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	4.0	0.0
Corporate debt securities
Total marketable available-for-sale debt securities
Amortized Cost	3,552.0	3,519.4
Gross Unrealized Gains	18.3	10.6
Gross Unrealized Losses	(0.8)	(4.1)
Fair Value	3,569.5	3,525.9
Commercial paper
Total marketable available-for-sale debt securities
Amortized Cost	3.5	5.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	(0.0)
Fair Value	3.5	5.0
Total marketable available-for-sale debt securities
Total marketable available-for-sale debt securities
Amortized Cost	6,631.1	6,608.4
Gross Unrealized Gains	32.5	19.8
Gross Unrealized Losses	(2.2)	(10.6)
Fair Value	$ 6,661.4	$ 6,617.6