Contingencies, Guarantees, Indemnifications and Leases - Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets
Operating lease assets	$ 194.7	$ 210.5
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Finance lease assets	$ 82.4	$ 94.2
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Total lease assets	$ 277.1	$ 304.7
Liabilities
Operating lease liabilities	$ 196.5	$ 209.9
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other Liabilities	Other Liabilities
Finance lease liabilities	$ 83.0	$ 94.8
Finance Lease, Liability, Statement of Financial Position [Extensible List]	Other Liabilities	Other Liabilities
Total lease liabilities	$ 279.5	$ 304.7
Finance lease cost:
Amortization of right-of-use assets	34.0	30.5	$ 20.5
Interest on lease liabilities	1.2	1.0	1.0
Operating lease cost	61.6	66.6	58.7
Other lease cost	12.4	10.8	8.6
Sublease income	(1.5)	(1.7)	(1.6)
Total lease cost	107.7	107.2	87.2
Payments for operating leases	58.3	63.0	71.6
Payments for finance leases	35.1	31.4	$ 21.2
Operating leases, payments due for the twelve months ending December 31:
2023	51.2
2024	41.1
2025	35.6
2026	30.9
2027	24.9
2028 and thereafter	37.0
Total lease payments	220.7
Less: interest	24.2
Present value of lease liabilities	196.5	209.9
Finance leases, payments due for the twelve months ending December 31:
2023	35.0
2024	30.2
2025	14.6
2026	5.0
2027	0.4
Total lease payments	85.2
Less: interest	2.2
Present value of lease liabilities	83.0	94.8
Total leases, payments due for the twelve months ending December 31:
2023	86.2
2024	71.3
2025	50.2
2026	35.9
2027	25.3
2028 and thereafter	37.0
Total lease payments	305.9
Less: interest	26.4
Present value of lease liabilities	$ 279.5	$ 304.7
Weighted-average remaining lease term and weighted-average discount rates
Weighted average remaining lease term, Operating leases	6 years 4 months 24 days	6 years 6 months	6 years 8 months 12 days
Weighted average remaining lease term, Finance leases	2 years 9 months 18 days	3 years 2 months 12 days	3 years
Weighted-average discount rate, Operating leases	3.60%	3.40%	3.20%
Weighted-average discount rate, Finance leases	1.70%	1.00%	1.80%