Fair Value Measurements - Schedule of Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Assets:
Cash equivalents	$ 2,121.6	$ 1,452.2
Available-for-sale debt securities	15,713.4	14,329.1
Equity securities	34.3	1,095.3
Total assets	17,869.3	16,876.6
Liabilities:
Contingent consideration	10.3	52.3
Restricted
Assets:
Equity securities	33.3	43.2
Corporate bonds
Assets:
Available-for-sale debt securities	10,219.5	8,220.6
U.S. government and government agency obligations
Assets:
Available-for-sale debt securities	4,367.3	4,817.0
Commercial paper
Assets:
Available-for-sale debt securities	541.1	548.7
Certificates of deposit
Assets:
Available-for-sale debt securities	265.9	381.1
Asset-backed securities
Assets:
Available-for-sale debt securities	242.8	279.3
Sovereign bonds
Assets:
Available-for-sale debt securities	76.8	82.4
Level 1
Assets:
Cash equivalents	1,127.7	1,264.2
Equity securities	34.3	1,095.3
Total assets	1,162.0	2,359.5
Liabilities:
Contingent consideration	0.0	0.0
Level 1 | Corporate bonds
Assets:
Available-for-sale debt securities	0.0	0.0
Level 1 | U.S. government and government agency obligations
Assets:
Available-for-sale debt securities	0.0	0.0
Level 1 | Commercial paper
Assets:
Available-for-sale debt securities	0.0	0.0
Level 1 | Certificates of deposit
Assets:
Available-for-sale debt securities	0.0	0.0
Level 1 | Asset-backed securities
Assets:
Available-for-sale debt securities	0.0	0.0
Level 1 | Sovereign bonds
Assets:
Available-for-sale debt securities	0.0	0.0
Level 2
Assets:
Cash equivalents	993.9	188.0
Equity securities	0.0	0.0
Total assets	16,707.3	14,517.1
Liabilities:
Contingent consideration	0.0	0.0
Level 2 | Corporate bonds
Assets:
Available-for-sale debt securities	10,219.5	8,220.6
Level 2 | U.S. government and government agency obligations
Assets:
Available-for-sale debt securities	4,367.3	4,817.0
Level 2 | Commercial paper
Assets:
Available-for-sale debt securities	541.1	548.7
Level 2 | Certificates of deposit
Assets:
Available-for-sale debt securities	265.9	381.1
Level 2 | Asset-backed securities
Assets:
Available-for-sale debt securities	242.8	279.3
Level 2 | Sovereign bonds
Assets:
Available-for-sale debt securities	76.8	82.4
Level 3
Assets:
Cash equivalents	0.0	0.0
Equity securities	0.0	0.0
Total assets	0.0	0.0
Liabilities:
Contingent consideration	10.3	52.3
Level 3 | Corporate bonds
Assets:
Available-for-sale debt securities	0.0	0.0
Level 3 | U.S. government and government agency obligations
Assets:
Available-for-sale debt securities	0.0	0.0
Level 3 | Commercial paper
Assets:
Available-for-sale debt securities	0.0	0.0
Level 3 | Certificates of deposit
Assets:
Available-for-sale debt securities	0.0	0.0
Level 3 | Asset-backed securities
Assets:
Available-for-sale debt securities	0.0	0.0
Level 3 | Sovereign bonds
Assets:
Available-for-sale debt securities	$ 0.0	$ 0.0