Consolidated Balance Sheet (Unaudited) (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheet
Property, accumulated depreciation	$ 4,967	$ 4,847	[1]
Other intangibles, accumulated amortization	$ 49	$ 49	[1]
Common stock, par value	$ 0.25	$ 0.25	[1]

[1] * Condensed from audited financial statements.