Segment Information (Reconciliation to income (loss) from continuing operations) (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]    
Gross profit $ 524 $ 448
Selling, general and administrative expenses (181) (168)
Merger related costs 27 (1)
Restructuring charge (1) [1] (1)
Non-rental depreciation and amortization (69) (60)
Interest expense, net (121) (125)
Other income, net 3 1
Income before provision for income taxes 182 94
Equipment rentals    
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]    
Gross profit 446 379
Other lines of business    
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]    
Gross profit $ 78 $ 69
[1] Reflected in our condensed consolidated statements of income as “Restructuring charge.” These charges are not allocated to our reportable segments.