Consolidated Balance Sheets Parenthetical - USD ($)
$ in Millions
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Restricted Cash and Cash Equivalents  
Allowance for doubtful accounts $ 4  
Common Stock, Value, Issued $ 0.01 $ 0.01  
Common Stock, Shares, Issued 100   100