Financial Instruments - Credit Facilities (Details)	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 77,000,000
Line of credit facility	0	$ 0
Commercial Paper	0	0
Other Short-term Borrowings	1,400,000	$ 0
Revolving Credit Facility
Line of Credit Facility [Line Items]
Revolving credit facility, current borrowing capacity	1,000,000,000.0
Line of credit facility, maximum borrowing capacity	$ 1,500,000,000
Operational Efficiency [Member]
Line of Credit Facility [Line Items]
Maximum total leverage ratio	3.50
Maximum total leverage ratio	4.00