v2.4.0.6
CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)
In Millions, except Share data, unless otherwise specified
Mar. 31, 2012
Dec. 31, 2011
CONDENSED CONSOLIDATED BALANCE SHEETS    
Trade accounts receivable, allowance (in dollars) $ 115 $ 113
Convertible perpetual preference shares, par value (in dollars per share) $ 0.01 $ 0.01
Convertible perpetual preference shares, authorized 6,900,000 6,900,000
Convertible perpetual preference shares, shares issued 6,900,000 6,900,000
Convertible perpetual preference shares, shares outstanding 6,900,000 6,900,000
Convertible perpetual preference shares, liquidation preference (in dollars per share) $ 100 $ 100
Common shares, par value (in dollars per share) $ 0.01 $ 0.01
Common shares, authorized 400,000,000 400,000,000
Common shares, issued 145,907,590 145,610,029
Common shares, outstanding 145,907,590 145,610,029
Treasury shares 1,933,286 1,933,286