Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Nov. 30, 2011	May 31, 2011
CURRENT ASSETS
Allowances for receivables	$ 91	$ 83
Allowances for spare parts, supplies and fuel	$ 176	$ 169
OWNER'S EQUITY
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	1,000	1,000
Common stock, shares issued	1,000	1,000
Common stock, shares outstanding	1,000	1,000