NOTES PAYABLE, LONG-TERM DEBT AND AVAILABLE CREDIT FACILITIES Committed and Available Credit Facilities (Details) € in Millions, $ in Millions	Apr. 05, 2019 USD ($)	May 31, 2016 USD ($)	Mar. 31, 2019 EUR (€)	Mar. 31, 2019 USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 12,130
Line of Credit Facility, Remaining Borrowing Capacity				7,630
DCC Term Loan Facility [Domain] | Term Loan Facility [Domain]
Line of Credit Facility [Line Items]
Proceeds from Lines of Credit		$ 4,500
Term Loan Facility, Due April 2019 [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Repayments of Debt	$ 2,000
Term Loan Facility, Due April 2019 [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				2,000
Line of Credit Facility, Remaining Borrowing Capacity				0
Term Loan Facility, Due December 2021 [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				2,500
Line of Credit Facility, Remaining Borrowing Capacity				0
Five Year Competitive Advance and Revolving Credit Facility [Member] | 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
North American Securitization Facility, Due September 2019 [Member] | Secured Debt [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				800
Line of Credit Facility, Remaining Borrowing Capacity				800
European Securitization Facility, Due October 2020 [Member] | Secured Debt [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			€ 400	450
Line of Credit Facility, Remaining Borrowing Capacity				450
Bilateral Revolving Credit Facility, Due October 2019 [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				100
Line of Credit Facility, Remaining Borrowing Capacity				100
Bilateral Revolving Credit Facility, Due March 2020, Facility One [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				100
Line of Credit Facility, Remaining Borrowing Capacity				100
Bilateral Revolving Credit Facility, Due March 2020, Facility Two [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				100
Line of Credit Facility, Remaining Borrowing Capacity				100
Bilateral Revolving Credit Facility, Due March 2020, Facility Three [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				280
Line of Credit Facility, Remaining Borrowing Capacity				280
Bilateral Revolving Credit Facility, Due March 2020, Facility Four [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				100
Line of Credit Facility, Remaining Borrowing Capacity				100
Bilateral Revolving Credit Facility, Due March 2020, Facility Five [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				200
Line of Credit Facility, Remaining Borrowing Capacity				200
Bilateral Revolving Credit Facility, Due May 2020 [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				200
Line of Credit Facility, Remaining Borrowing Capacity				200
Bilateral Revolving Credit Facility, Due July 2020 [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				200
Line of Credit Facility, Remaining Borrowing Capacity				200
Bilateral Revolving Credit Facility, Due August 2020 [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				100
Line of Credit Facility, Remaining Borrowing Capacity				$ 100