XML 22 R28.htm IDEA: XBRL DOCUMENT v2.4.0.8
Accounts Receivable, Net (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2014
Dec. 31, 2013
Receivables [Abstract]    
Allowance for bill adjustments and uncollectible accounts $ 50 $ 54
Accounts receivable greater than 90 days old $ 52 $ 50