Marketable Securities - Schedule of Fair Value and Unrealized Losses of Debt Securities (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	$ 5,413.5	$ 3,300.9
Unrealized Loss - Less than 12 months	(52.2)	(76.9)
Fair Value - 12 Months or Greater	4,517.0	4,332.2
Unrealized Loss - 12 Months or Greater	(171.8)	(225.9)
Fair Value - Total	9,930.5	7,633.1
Unrealized Loss - Total	(224.0)	(302.8)
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	1,976.1	2,445.4
Unrealized Loss - Less than 12 months	(23.8)	(73.1)
Fair Value - 12 Months or Greater	4,387.1	4,200.4
Unrealized Loss - 12 Months or Greater	(165.3)	(218.0)
Fair Value - Total	6,363.2	6,645.8
Unrealized Loss - Total	(189.1)	(291.1)
U.S. government and government agency obligations
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	2,794.8	785.2
Unrealized Loss - Less than 12 months	(26.8)	(2.0)
Fair Value - 12 Months or Greater	51.7	71.0
Unrealized Loss - 12 Months or Greater	(3.7)	(4.9)
Fair Value - Total	2,846.5	856.2
Unrealized Loss - Total	(30.5)	(6.9)
Sovereign bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	12.2	18.6
Unrealized Loss - Less than 12 months	(0.2)	(1.1)
Fair Value - 12 Months or Greater	53.3	45.6
Unrealized Loss - 12 Months or Greater	(1.5)	(1.9)
Fair Value - Total	65.5	64.2
Unrealized Loss - Total	(1.7)	(3.0)
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	431.8
Unrealized Loss - Less than 12 months	(0.2)
Fair Value - 12 Months or Greater	0.0
Unrealized Loss - 12 Months or Greater	0.0
Fair Value - Total	431.8
Unrealized Loss - Total	(0.2)
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	136.3	40.2
Unrealized Loss - Less than 12 months	(0.1)	(0.1)
Fair Value - 12 Months or Greater	0.0	0.0
Unrealized Loss - 12 Months or Greater	0.0	0.0
Fair Value - Total	136.3	40.2
Unrealized Loss - Total	(0.1)	(0.1)
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	62.3	11.5
Unrealized Loss - Less than 12 months	(1.1)	(0.6)
Fair Value - 12 Months or Greater	24.9	15.2
Unrealized Loss - 12 Months or Greater	(1.3)	(1.1)
Fair Value - Total	87.2	26.7
Unrealized Loss - Total	$ (2.4)	$ (1.7)