Guarantees (Details 2)	Sep. 30, 2021 USD ($)
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	$ 147,600,000
Fixed maximum amounts guaranteed by year 2021	900,000
Fixed maximum amounts guaranteed by year 2022	39,300,000
Fixed maximum amounts guaranteed by year 2023	50,300,000
Fixed maximum amounts guaranteed by year 2024	46,600,000
Fixed maximum amounts guaranteed by year 2025	600,000
Fixed maximum amounts guaranteed, thereafter	900,000
No scheduled maturity date	9,000,000
Amount outstanding under guarantees that is reflected on balance sheet	0
Letters of credit	25,500,000
Letters of credit set to expire - 2021	21,200,000
Letters of credit set to expire - 2022	4,300,000
Outstanding letters of credit	0
Amount of surety bonds outstanding	$ 897,200,000