Marketable Securities and Equity Investments - Schedule of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2026	Dec. 31, 2025
Cash equivalents
Amortized Cost	$ 2,569.8	$ 2,779.1
Fair Value	2,569.8	2,779.1
Total marketable available-for-sale debt securities
Gross  Unrealized  Losses	(13.2)
Corporate equity securities
Amortized Cost	25.0	25.0
Gross  Unrealized  Gains	0.0	0.0
Gross  Unrealized  Losses	(4.6)	(8.4)
Fair Value	20.4	16.6
Amortized Cost	7,504.6	7,200.3
Gross  Unrealized  Gains	16.9	44.3
Gross  Unrealized  Losses	(17.8)	(9.0)
Fair Value	7,503.7	7,235.6
Total cash equivalents and marketable securities, Amortized Cost	10,074.4	9,979.4
Total cash equivalents and marketable securities, Gross Unrealized Gains	16.9	44.3
Total cash equivalents and marketable securities, Gross Unrealized Losses	(17.8)	(9.0)
Total cash equivalents and marketable securities, Fair Value	10,073.5	10,014.7
U.S. Treasury securities
Total marketable available-for-sale debt securities
Amortized Cost	1,744.9	1,852.9
Gross  Unrealized  Gains	2.8	12.1
Gross  Unrealized  Losses	(2.9)	(0.1)
Fair Value	1,744.8	1,864.9
U.S. government agency securities
Total marketable available-for-sale debt securities
Amortized Cost	207.8	261.2
Gross  Unrealized  Gains	0.6	1.2
Gross  Unrealized  Losses	(0.2)	0.0
Fair Value	208.2	262.4
Asset-backed securities
Total marketable available-for-sale debt securities
Amortized Cost	1,293.2	1,351.1
Gross  Unrealized  Gains	2.6	6.0
Gross  Unrealized  Losses	(2.2)	(0.1)
Fair Value	1,293.6	1,357.0
Certificates of deposit
Total marketable available-for-sale debt securities
Amortized Cost	36.6	26.2
Gross  Unrealized  Gains	0.0	0.0
Gross  Unrealized  Losses	0.0	0.0
Fair Value	36.6	26.2
Corporate debt securities
Total marketable available-for-sale debt securities
Amortized Cost	4,167.5	3,669.3
Gross  Unrealized  Gains	10.9	25.0
Gross  Unrealized  Losses	(7.9)	(0.4)
Fair Value	4,170.5	3,693.9
Commercial paper
Total marketable available-for-sale debt securities
Amortized Cost	29.6	14.6
Gross  Unrealized  Gains	0.0	0.0
Gross  Unrealized  Losses	0.0	0.0
Fair Value	29.6	14.6
Total marketable available-for-sale debt securities
Total marketable available-for-sale debt securities
Amortized Cost	7,479.6	7,175.3
Gross  Unrealized  Gains	16.9	44.3
Gross  Unrealized  Losses	(13.2)	(0.6)
Fair Value	$ 7,483.3	$ 7,219.0

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2