Debt - Long-term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Long-term debt
Total long-term debt	$ 9,591.6	$ 8,851.5	$ 8,292.0
Less amounts due within one year	0.6	260.6	25.1
Long-term debt	9,591.0	8,590.9	8,266.9
Capitalized debt issuance costs	57.3	57.6	52.9
3.45% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 1,492.1	1,490.4	1,488.6
Interest rate	3.45%
4.50% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 1,232.3	1,231.6	1,230.8
Interest rate	4.50%
2.95% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 793.6	792.6	791.7
Interest rate	2.95%
4.05% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 596.9	0.0	0.0
Interest rate	4.05%
3.80% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 543.2	543.0	542.8
Interest rate	3.80%
3.125% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 499.0	498.3	497.7
Interest rate	3.125%
2.30% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 496.7	496.2	495.8
Interest rate	2.30%
2.20% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 494.2	493.6	0.0
Interest rate	2.20%
3.30% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 494.1	493.9	493.7
Interest rate	3.30%
2.90% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 491.5	491.3	0.0
Interest rate	2.90%
3.45% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 399.1	398.7	398.3
Interest rate	3.45%
4.25% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 397.7	0.0	0.0
Interest rate	4.25%
4.55% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 395.0	394.7	394.5
Interest rate	4.55%
3.95% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 354.7	356.2	357.8
Interest rate	3.95%
4.00% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 296.9	296.7	296.6
Interest rate	4.00%
3.30% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 249.8	249.6	249.5
Interest rate	3.30%
4.40% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 240.5	240.0	239.6
Interest rate	4.40%
7.375% Debentures | Debentures
Long-term debt
Total long-term debt	$ 119.2	119.2	119.1
Interest rate	7.375%
7.45% Debentures | Debentures
Long-term debt
Total long-term debt	$ 3.5	3.5	3.5
Interest rate	7.45%
0.53% to 8.00% Promissory Notes | Debentures
Long-term debt
Total long-term debt	$ 1.6	2.0	2.3
0.53% to 8.00% Promissory Notes | Debentures | Minimum
Long-term debt
Interest rate	0.53%
0.53% to 8.00% Promissory Notes | Debentures | Maximum
Long-term debt
Interest rate	8.00%
2.75% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 0.0	260.0	259.6
Interest rate	2.75%
4.20% Senior Notes | Senior Notes
Long-term debt
Total long-term debt	$ 0.0	0.0	405.7
Interest rate	4.20%
0.92% Fixed Rate Loan | Debentures
Long-term debt
Total long-term debt	$ 0.0	$ 0.0	$ 24.4
Interest rate	0.92%