Guarantees (Details 2)	Sep. 30, 2023 USD ($)
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	$ 330,800,000
Fixed maximum amounts guaranteed by year 2023	9,500,000
Fixed maximum amounts guaranteed by year 2024	67,400,000
Fixed maximum amounts guaranteed by year 2025	251,100,000
Fixed maximum amounts guaranteed by year 2026	1,500,000
Fixed maximum amounts guaranteed by year 2027	1,000,000
Fixed maximum amounts guaranteed, thereafter	300,000
Amount outstanding under guarantees that is reflected on balance sheet	0
Letters of credit	11,100,000
Outstanding letters of credit	0
Letters of credit set to expire - 2023	8,900,000
Letters of credit set to expire - 2024	2,200,000
Amount of surety bonds outstanding	$ 330,800,000