Debt (Long Term Debt Narrative) (Details) (USD $)
Share data in Millions, except Per Share data, unless otherwise specified
12 Months Ended 1 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended
Dec. 31, 2014
Jun. 30, 2008
Oct. 31, 2010
Oct. 31, 2012
Mar. 31, 2014
Mar. 30, 2012
Jan. 31, 2011
Nov. 30, 2009
Dec. 31, 2012
Jan. 21, 2015
Dec. 31, 2018
Dec. 31, 2015
Dec. 31, 2020
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2019
Dec. 31, 2013
Mar. 31, 2012
$2.3 billion ABL Facility                                    
Debt Instrument [Line Items]                                    
Maximum revolving credit amount percentage 10.00%                                  
Debt terms reference amount to maximum revolving credit $ 150,000,000                                  
8 3/8 percent Senior Subordinated Notes                                    
Debt Instrument [Line Items]                                    
Stated interest rate 8.375%                                  
6 1/8 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount       400,000,000                            
Stated interest rate 6.125%                                  
5 3/4 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Stated interest rate 5.75%                                  
4 percent Convertible Senior Notes                                    
Debt Instrument [Line Items]                                    
Stated interest rate 4.00%               4.00%               4.00%  
Effective interest rate 7.30%                                  
Debt instrument, convertible, conversion price $ 11.11                                  
8 1/4 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Stated interest rate 8.25%                                  
5 3/4 percent Senior Secured Notes                                    
Debt Instrument [Line Items]                                    
Stated interest rate 5.75%                                  
7 3/8 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Stated interest rate 7.375%                                  
7 5/8 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Stated interest rate 7.625%                                  
Subsidiaries | $2.3 billion ABL Facility                                    
Debt Instrument [Line Items]                                    
Line of credit facility, maximum borrowing capacity 2,300,000,000                                  
Credit facility | Line of credit | $2.3 billion ABL Facility                                    
Debt Instrument [Line Items]                                    
Debt instrument, term   5 years                                
Line of credit facility, maximum borrowing capacity   1,250,000,000                             2,300,000,000  
Line of credit facility, average outstanding amount 1,100,000,000                                  
Line of credit facility, interest rate during period 2.30%                                  
Line of credit facility, maximum month-end outstanding amount 1,300,000,000                                  
Senior subordinated notes | 8 3/8 percent Senior Subordinated Notes                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount     750,000,000                              
Proceeds from issuance of long-term debt     732,000,000                              
Debt Instrument, Redemption Price, Percentage     101.00%                              
Senior notes | 6 1/8 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount 925,000,000                                  
Proceeds from issuance of long-term debt       939,000,000                            
Debt Instrument, Redemption Price, Percentage       101.00%                            
Effective interest rate 5.70%                                  
Senior notes | Add-on to Senior Notes 6 1/8 percent                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount         525,000,000                          
Debt instrument, unamortized premium 26,000,000                                  
Senior notes | 5 3/4 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount         850,000,000                          
Proceeds from issuance of long-term debt         837,000,000                          
Debt Instrument, Redemption Price, Percentage         101.00%                          
Senior notes | 7 3/8 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount                                   750,000,000
Proceeds from issuance of long-term debt           732,000,000                        
Debt Instrument, Redemption Price, Percentage           101.00%                        
Senior notes | 7 5/8 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount                                   1,325,000,000
Proceeds from issuance of long-term debt           1,295,000,000                        
Debt Instrument, Redemption Price, Percentage           101.00%                        
Senior notes | RSC Holdings Inc | 8 1/4 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount             650,000,000                      
Debt Instrument, Redemption Price, Percentage             101.00%                      
Effective interest rate 7.00%                                  
Debt instrument, unamortized discount 37,000,000                                  
Senior secured notes | 5 3/4 percent Senior Secured Notes                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount                                   750,000,000
Proceeds from issuance of long-term debt           733,000,000                        
Debt Instrument, Redemption Price, Percentage           101.00%                        
12-month period commencing on May 15, 2019 | Senior notes | 5 3/4 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt Instrument, Redemption Price, Percentage         102.875%                          
12-month period commencing on May 15, 2022 | Senior notes | 5 3/4 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt Instrument, Redemption Price, Percentage         100.00%                          
Convertible debt                                    
Debt Instrument [Line Items]                                    
Debt instrument convertible, shares issued 3                                  
Debt instrument effective conversion price $ 15.56                                  
Convertible debt | 4 percent Convertible Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt instrument, face amount 34,000,000             173,000,000                    
Stated interest rate 4.00%             4.00% 4.00%               4.00%  
Proceeds from issuance of long-term debt               167,000,000                    
Debt Instrument, Redemption Price, Percentage 100.00%                                  
Effective interest rate 11.60%                                  
Debt instrument, convertible, conversion price $ 11.11                                  
Debt Instrument, Convertible, Value if Converted 310,000,000                                  
Derivative cost of hedge               26,000,000                    
Debt instrument convertible if converted price per share $ 102.01                                  
Debt instrument convertible if converted value, non-cash 276,000,000                                  
Cost to convert convertible notes 3,000,000                                  
Change in stock price to settle convertible debt per share $ 1                                  
Debt conversion, hedged converted instrument, cash and non-cash receivable 3,000,000                                  
Debt instrument convertible, hedged, if converted price per share $ 12.10                                  
Debt instrument, unamortized discount 2,000,000                                  
Convertible note hedge transactions, net               17,000,000 33,000,000                  
Proceeds from convertible debt 173,000,000                                  
Convertible note hedge transaction shares 0.7                                  
Shares to be issued, hypothetical share price one 2.6                                  
Shares to be issued, hypothetical share price two 2.7                                  
Percentage premium over price at issuance 75.00%                                  
Closing price at issuance $ 8.89                                  
Debt conversion, hypothetical market price per share one $ 80.00                                  
Debt conversion, hypothetical market price per share two $ 100.00                                  
Convertible debt | Subsequent event | 4 percent Convertible Senior Notes                                    
Debt Instrument [Line Items]                                    
Redemption notice amount                   $ 26,000,000                
Forecast | Senior subordinated notes | 8 3/8 percent Senior Subordinated Notes                                    
Debt Instrument [Line Items]                                    
Debt Instrument, Redemption Price, Percentage                     100.00% 104.188%            
Forecast | Senior notes | 6 1/8 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt Instrument, Redemption Price, Percentage                         100.00% 103.063%        
Forecast | Senior notes | 7 3/8 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt Instrument, Redemption Price, Percentage                     100.00%       103.688%      
Forecast | Senior notes | 7 5/8 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt Instrument, Redemption Price, Percentage                         100.00% 103.813%        
Forecast | Senior notes | RSC Holdings Inc | 8 1/4 percent Senior Notes                                    
Debt Instrument [Line Items]                                    
Debt Instrument, Redemption Price, Percentage                             104.125% 100.00%    
Forecast | Senior secured notes | 5 3/4 percent Senior Secured Notes                                    
Debt Instrument [Line Items]                                    
Debt Instrument, Redemption Price, Percentage                       102.875%   100.00%