Financial Instruments (Details 2) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Summary of Contractual Maturities: Available-for-Sale Securities
Due in one year or less, amortized cost	$ 3,468.2	$ 1,483.3
Due in one year or less, estimated fair value	3,460.5	1,473.5
Due after one year through five years, amortized cost	1,202.9	703.7
Due after one year through five years, estimated fair value	1,192.9	694.4
Due after five years, amortized cost	15.7	12.1
Due after five years, estimated fair value	15.1	11.3
Marketable debt securities	4,668.5	2,179.2
Amortized Cost	$ 4,686.8	$ 2,199.1