XML 41 R27.htm IDEA: XBRL DOCUMENT v2.4.0.6
Fair Value of Financial Instruments (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2012
Dec. 31, 2011
Fair Value of Financial Instruments [Abstract]    
Carrying amount of long-term debt $ 541 $ 507
Fair value of long-term debt $ 564 $ 532