Marketable Securities and Equity Investments - Schedule of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Cash equivalents
Amortized Cost	$ 1,216.6	$ 1,687.1
Fair Value	1,216.6	1,687.1
Total marketable available-for-sale debt securities
Gross Unrealized Losses	(0.8)
Corporate equity securities
Amortized Cost	25.0	72.1
Gross Unrealized Gains	0.0	3.0
Gross Unrealized Losses	(15.6)	(38.5)
Fair Value	9.4	36.6
Amortized Cost	7,041.5	6,680.5
Gross Unrealized Gains	45.1	22.8
Gross Unrealized Losses	(16.4)	(49.1)
Fair Value	7,070.2	6,654.2
Total cash equivalents and marketable securities, Amortized Cost	8,258.1	8,367.6
Total cash equivalents and marketable securities, Gross Unrealized Gains	45.1	22.8
Total cash equivalents and marketable securities, Gross Unrealized Losses	(16.4)	(49.1)
Total cash equivalents and marketable securities, Fair Value	8,286.8	8,341.3
U.S. Treasury securities
Total marketable available-for-sale debt securities
Amortized Cost	1,926.0	1,603.9
Gross Unrealized Gains	11.9	3.6
Gross Unrealized Losses	(0.2)	(5.5)
Fair Value	1,937.7	1,602.0
U.S. government agency securities
Total marketable available-for-sale debt securities
Amortized Cost	189.6	240.5
Gross Unrealized Gains	1.1	0.5
Gross Unrealized Losses	(0.1)	(0.5)
Fair Value	190.6	240.5
Asset-backed securities
Total marketable available-for-sale debt securities
Amortized Cost	1,354.6	1,239.6
Gross Unrealized Gains	6.6	5.1
Gross Unrealized Losses	(0.2)	(0.5)
Fair Value	1,361.0	1,244.2
Certificates of deposit
Total marketable available-for-sale debt securities
Amortized Cost	24.4	0.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	24.4	0.0
Corporate debt securities
Total marketable available-for-sale debt securities
Amortized Cost	3,513.2	3,519.4
Gross Unrealized Gains	25.5	10.6
Gross Unrealized Losses	(0.3)	(4.1)
Fair Value	3,538.4	3,525.9
Commercial paper
Total marketable available-for-sale debt securities
Amortized Cost	8.7	5.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	8.7	5.0
Total marketable available-for-sale debt securities
Total marketable available-for-sale debt securities
Amortized Cost	7,016.5	6,608.4
Gross Unrealized Gains	45.1	19.8
Gross Unrealized Losses	(0.8)	(10.6)
Fair Value	$ 7,060.8	$ 6,617.6