Financing Arrangements	6 Months Ended
Nov. 30, 2015
Financing Arrangements [Abstract]
Financing Arrangements	(3) Financing Arrangements We have a shelf registration statement with the SEC that allows us to sell, in one or more future offerings, any combination of our unsecured debt securities and common stock. During the quarter, we issued $1.25 billion of senior unsecured 4.75% fixed-rate notes due in November 2045 under our current shelf registration statement. Interest on the notes is paid semiannually. We utilized the net proceeds for working capital and general corporate purposes, including share repurchases made pursuant to our current share repurchase authorization. On November 13, 2015, we replaced our revolving and letter of credit facilities with a new, single five-year $1.75 billion revolving credit facility that expires in November 2020. The facility, which includes a $500 million letter of credit sublimit, is available to finance our operations and other cash flow needs. The agreement contains a financial covenant, which requires us to maintain a ratio of debt to consolidated earnings (excluding non-cash pension mark-to-market adjustments and non-cash asset impairment charges) before interest, taxes, depreciation and amortization (“EBITDA”) of not more than 3.5 to 1.0, calculated as of the end of the applicable quarter on a rolling four quarters basis. The ratio of our debt to EBITDA was 1.2 to 1.0 at November 30, 2015. We believe the leverage ratio covenant is our only significant restrictive covenant in our revolving credit agreement. Our revolving credit agreement contains other customary covenants that do not, individually or in the aggregate, materially restrict the conduct of our business. We are in compliance with the leverage ratio covenant and all other covenants of our revolving credit agreement and do not expect the covenants to affect our operations, including our liquidity or expected funding needs. As of November 30, 2015, no commercial paper was outstanding. However, we had a total of $318 million in letters of credit outstanding at November 30, 2015, with $182 million of the letter of credit sublimit unused under our revolving credit facility. Long-term debt, exclusive of capital leases, had carrying values of $8.5 billion at November 30, 2015 and $7.2 billion at May 31, 2015, compared with estimated fair values of $8.5 billion at November 30, 2015 and $7.4 billion at May 31, 2015. The estimated fair values were determined based on quoted market prices and the current rates offered for debt with similar terms and maturities. The fair value of our long-term debt is classified as Level 2 within the fair value hierarchy. This classification is defined as a fair value determined using market-based inputs other than quoted prices that are observable for the liability, either directly or indirectly.

Financing Arrangements

6 Months Ended

Nov. 30, 2015

(3) Financing Arrangements

We have a shelf registration statement with the SEC that allows us to sell, in one or more future offerings, any combination of our unsecured debt securities and common stock.

During the quarter, we issued $1.25 billion of senior unsecured 4.75% fixed-rate notes due in November 2045 under our current shelf registration statement. Interest on the notes is paid semiannually. We utilized the net proceeds for working capital and general corporate purposes, including share repurchases made pursuant to our current share repurchase authorization.

On November 13, 2015, we replaced our revolving and letter of credit facilities with a new, single five-year $1.75 billion revolving credit facility that expires in November 2020. The facility, which includes a $500 million letter of credit sublimit, is available to finance our operations and other cash flow needs. The agreement contains a financial covenant, which requires us to maintain a ratio of debt to consolidated earnings (excluding non-cash pension mark-to-market adjustments and non-cash asset impairment charges) before interest, taxes, depreciation and amortization (“EBITDA”) of not more than 3.5 to 1.0, calculated as of the end of the applicable quarter on a rolling four quarters basis. The ratio of our debt to EBITDA was 1.2 to 1.0 at November 30, 2015. We believe the leverage ratio covenant is our only significant restrictive covenant in our revolving credit agreement. Our revolving credit agreement contains other customary covenants that do not, individually or in the aggregate, materially restrict the conduct of our business. We are in compliance with the leverage ratio covenant and all other covenants of our revolving credit agreement and do not expect the covenants to affect our operations, including our liquidity or expected funding needs. As of November 30, 2015, no commercial paper was outstanding. However, we had a total of $318 million in letters of credit outstanding at November 30, 2015, with $182 million of the letter of credit sublimit unused under our revolving credit facility.

Long-term debt, exclusive of capital leases, had carrying values of $8.5 billion at November 30, 2015 and $7.2 billion at May 31, 2015, compared with estimated fair values of $8.5 billion at November 30, 2015 and $7.4 billion at May 31, 2015. The estimated fair values were determined based on quoted market prices and the current rates offered for debt with similar terms and maturities. The fair value of our long-term debt is classified as Level 2 within the fair value hierarchy. This classification is defined as a fair value determined using market-based inputs other than quoted prices that are observable for the liability, either directly or indirectly.