Consolidated Statements of Equity (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Mar. 31, 2010	Dec. 31, 2009	Jun. 30, 2009
Consolidated Statements of Equity [Abstract]
Common stock, par value	$ 1	$ 1	$ 1	$ 1	$ 1
Common stock, authorized shares	480	480		480