Marketable Securities - Schedule of Fair Value and Unrealized Losses of Debt Securities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	$ 7,854.9	$ 3,300.9
Unrealized Loss - Less than 12 months	(9.0)	(76.9)
Fair Value - 12 Months or Greater	4,157.5	4,332.2
Unrealized Loss - 12 Months or Greater	(106.8)	(225.9)
Fair Value - Total	12,012.4	7,633.1
Unrealized Loss - Total	(115.8)	(302.8)
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	2,363.3	2,445.4
Unrealized Loss - Less than 12 months	(2.4)	(73.1)
Fair Value - 12 Months or Greater	4,034.7	4,200.4
Unrealized Loss - 12 Months or Greater	(102.5)	(218.0)
Fair Value - Total	6,398.0	6,645.8
Unrealized Loss - Total	(104.9)	(291.1)
U.S. government and government agency obligations
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	4,780.6	785.2
Unrealized Loss - Less than 12 months	(6.0)	(2.0)
Fair Value - 12 Months or Greater	52.7	71.0
Unrealized Loss - 12 Months or Greater	(2.6)	(4.9)
Fair Value - Total	4,833.3	856.2
Unrealized Loss - Total	(8.6)	(6.9)
Sovereign bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	12.4	18.6
Unrealized Loss - Less than 12 months	(0.1)	(1.1)
Fair Value - 12 Months or Greater	44.8	45.6
Unrealized Loss - 12 Months or Greater	(0.8)	(1.9)
Fair Value - Total	57.2	64.2
Unrealized Loss - Total	(0.9)	(3.0)
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	636.8
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	636.8
Unrealized Loss - Total	(0.2)
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months		40.2
Unrealized Loss - Less than 12 months		(0.1)
Fair Value - 12 Months or Greater		0.0
Unrealized Loss - 12 Months or Greater		0.0
Fair Value - Total		40.2
Unrealized Loss - Total		(0.1)
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	61.8	11.5
Unrealized Loss - Less than 12 months	(0.3)	(0.6)
Fair Value - 12 Months or Greater	25.3	15.2
Unrealized Loss - 12 Months or Greater	(0.9)	(1.1)
Fair Value - Total	87.1	26.7
Unrealized Loss - Total	$ (1.2)	$ (1.7)