NOTES PAYABLE, LONG-TERM DEBT AND AVAILABLE CREDIT FACILITIES Committed and Available Credit Facilities (Details) $ in Millions	Jun. 30, 2021 USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 8,100
Line of Credit Facility, Remaining Borrowing Capacity	8,100
Revolving Credit Facility [Member] | Five Year Competitive Advance and Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	5,000
Line of Credit Facility, Remaining Borrowing Capacity	5,000
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due December 2021, Facility One
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	300
Line of Credit Facility, Remaining Borrowing Capacity	300
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due December 2021, Facility Two
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	300
Line of Credit Facility, Remaining Borrowing Capacity	300
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due March 2022 [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	150
Line of Credit Facility, Remaining Borrowing Capacity	150
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due June 2022
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	100
Line of Credit Facility, Remaining Borrowing Capacity	100
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due September 2022. Facility One
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	200
Line of Credit Facility, Remaining Borrowing Capacity	200
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due November 2022
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	200
Line of Credit Facility, Remaining Borrowing Capacity	200
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due September 2023, Facility One
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	200
Line of Credit Facility, Remaining Borrowing Capacity	200
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due September 2023, Facility Two
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	250
Line of Credit Facility, Remaining Borrowing Capacity	250
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due September 2023, Facility Three
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	300
Line of Credit Facility, Remaining Borrowing Capacity	300
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due October 2024, Facility One [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	100
Line of Credit Facility, Remaining Borrowing Capacity	100
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due October 2024, Facility Two [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	100
Line of Credit Facility, Remaining Borrowing Capacity	100
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due November 2024 [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	200
Line of Credit Facility, Remaining Borrowing Capacity	200
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due March 2025, Facility One [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	100
Line of Credit Facility, Remaining Borrowing Capacity	100
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due March 2025, Facility Two [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	250
Line of Credit Facility, Remaining Borrowing Capacity	250
Revolving Credit Facility [Member] | Bilateral Revolving Credit Facility, Due March 2025, Facility Three [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	350
Line of Credit Facility, Remaining Borrowing Capacity	$ 350