Marketable Securities - Schedule of Fair Value and Unrealized Losses of Debt Securities (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	$ 8,674.9	$ 6,516.3
Unrealized Loss - Less than 12 months	(202.9)	(42.3)
Fair Value - 12 Months or Greater	214.1	0.0
Unrealized Loss - 12 Months or Greater	(13.3)	0.0
Fair Value - Total	8,889.0	6,516.3
Unrealized Loss - Total	(216.2)	(42.3)
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	7,269.3	5,889.3
Unrealized Loss - Less than 12 months	(194.2)	(40.9)
Fair Value - 12 Months or Greater	212.9	0.0
Unrealized Loss - 12 Months or Greater	(13.2)	0.0
Fair Value - Total	7,482.2	5,889.3
Unrealized Loss - Total	(207.4)	(40.9)
U.S. government and government agency obligations
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	326.2	90.0
Unrealized Loss - Less than 12 months	(3.8)	(0.8)
Fair Value - 12 Months or Greater	1.2	0.0
Unrealized Loss - 12 Months or Greater	(0.1)	0.0
Fair Value - Total	327.4	90.0
Unrealized Loss - Total	(3.9)	(0.8)
Sovereign bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	44.7	37.0
Unrealized Loss - Less than 12 months	(1.5)	(0.3)
Fair Value - 12 Months or Greater	0.0	0.0
Unrealized Loss - 12 Months or Greater	0.0	0.0
Fair Value - Total	44.7	37.0
Unrealized Loss - Total	(1.5)	(0.3)
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	666.5	295.7
Unrealized Loss - Less than 12 months	(1.3)	(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	666.5	295.7
Unrealized Loss - Total	(1.3)	(0.1)
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	324.5	169.4
Unrealized Loss - Less than 12 months	(0.9)	(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	324.5	169.4
Unrealized Loss - Total	(0.9)	(0.1)
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	43.7	34.9
Unrealized Loss - Less than 12 months	(1.2)	(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	43.7	34.9
Unrealized Loss - Total	$ (1.2)	$ (0.1)