Leases (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Oct. 01, 2019
Lessee, Lease, Description [Line Items]
Right of Use Asset in Exchange for New Lease Liability	$ 0
Lease Payments	$ 22,475
Weighted Average Remaining Lease Term	7 years 4 months 24 days
Weighted Average Discount Rate	3.39%
Cash Paid for Operating Liabilities	$ 5,300
Buildings and Property [Member]
Lessee, Lease, Description [Line Items]
Non-Cancelable Lease Term	10 years
Operating Lease Renewal Term	18 months
Lease Payments	$ 8,400
Buildings and Property [Member] | Minimum [Member]
Lessee, Lease, Description [Line Items]
Non-Cancelable Lease Term	1 month
Operating Lease Renewal Term	1 year
Buildings and Property [Member] | Maximum [Member]
Lessee, Lease, Description [Line Items]
Non-Cancelable Lease Term	10 years
Operating Lease Renewal Term	14 years
Drilling Rigs [Member] | Maximum [Member]
Lessee, Lease, Description [Line Items]
Non-Cancelable Lease Term	1 year
Guidance for Leases [Member]
Lessee, Lease, Description [Line Items]
Increase in Assets and Liabilities Upon Adoption of Leasing Standard		$ 19,700