NOTES PAYABLE, LONG-TERM DEBT AND AVAILABLE CREDIT FACILITIES NOTES PAYABLE, LONG-TERM DEBT AND AVAILABLE CREDIT FACILITIES (Schedule of Committed and Available Credit Facilities) (Details) - USD ($) $ in Millions	Jul. 20, 2016	Jun. 30, 2016
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 10,680
Line of Credit Facility, Remaining Borrowing Capacity		6,180
Five Year Competitive Advance and Revolving Credit Facility Agreement [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
$100M Revolving Credit Facility Due 3/2017 [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		100
Line of Credit Facility, Remaining Borrowing Capacity		100
$100M Revolving Credit Facility Due 3/2020 [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		100
Line of Credit Facility, Remaining Borrowing Capacity		100
$280M Revolving Credit Facility Due 3/2020 [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		280
Line of Credit Facility, Remaining Borrowing Capacity		280
$100M Revolving Credit Facility Due 3/2020 [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		100
Line of Credit Facility, Remaining Borrowing Capacity		100
$100M Revolving Credit Facility Due 3/2020 [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		100
Line of Credit Facility, Remaining Borrowing Capacity		100
$200M Revolving Credit Facility due 3/2020 [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		200
Line of Credit Facility, Remaining Borrowing Capacity		200
$100M Revolving Credit Facility Due 8/2016 [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		100
Line of Credit Facility, Remaining Borrowing Capacity		100
$200M Revolving Credit Facility Due 5/2018 [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		200
Line of Credit Facility, Remaining Borrowing Capacity		200
DCC Term Loan Facility [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		4,500
Line of Credit Facility, Remaining Borrowing Capacity		$ 0
Subsequent Event [Member] | $200M Revolving Credit Facility Due 7/2018 [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 200
Line of Credit Facility, Remaining Borrowing Capacity	$ 200