| Commitments And Contingencies detail (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009 | |
| Commitments and Contingencies [Abstract] | |||
| Operating Leases, Future Minimum Payments Due, Current | $ 40 | ||
| Operating Leases, Rent Expense, Net | 46 | 38 | 36 | 
| Operating Leases, Future Minimum Payments, Due in Two Years | 35 | ||
| Operating Leases, Future Minimum Payments, Due in Three Years | 25 | ||
| Operating Leases, Future Minimum Payments, Due in Four Years | 22 | ||
| Operating Leases, Future Minimum Payments, Due in Five Years | 20 | ||
| Operating Leases, Future Minimum Payments, Due Thereafter | $ 113 | ||
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within one year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fifth year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fourth year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the third year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the second year of the balance sheet date relating to leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due after the fifth year from the balance sheet date on leases defined as operating. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 |