CONSOLIDATED BALANCE SHEET (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Receivables, allowances	$ 3	$ 4
Property and equipment, accumulated depreciation	$ 6,408	$ 6,327
Common shares, par value	$ 1.25	$ 1.25
Common shares, authorized	1,360,000,000	1,360,000,000
Common shares, issued	525,484,841	583,548,428
Common shares, outstanding	525,484,841	583,548,428
6.375 percent Mandatory Convertible Preference Shares, Series A
Preference shares, par value	$ 1.00	$ 1.00
Preference shares, liquidation	$ 50.00	$ 50.00
Preference shares, authorized	40,000,000	40,000,000
Preference shares, issued	13,800,000	13,800,000
Preference shares, outstanding	13,800,000	13,800,000