Derivatives (Narrative) (Details) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Swap USD ($) gal	Dec. 31, 2013 Swap USD ($) gal	Dec. 31, 2012 Swap USD ($) gal	Dec. 31, 2014 Foreign contracts CAD	Dec. 31, 2014 Cost of equipment rentals, excluding depreciation Designated as hedging instrument Swap USD ($)		Dec. 31, 2013 Cost of equipment rentals, excluding depreciation Designated as hedging instrument Swap USD ($)		Dec. 31, 2012 Cost of equipment rentals, excluding depreciation Designated as hedging instrument Swap USD ($)		Dec. 31, 2014 Diesel swap Swap gal
Derivative [Line Items]
Derivative, nonmonetary notional amount (in gallons)											5,400,000
Derivative purchases of underlying currency (in Canadian Dollars)				207
Hedging activities net cash flow impact	(41)	38	25
Gain (loss) on hedged item					$ (40)	[1],[2]	$ (38)	[1],[2]	$ (25)	[1],[2]
Derivative purchases of underlying commodity (in gallons)	10,500,000	9,700,000	6,300,000

[1] Amounts recognized on hedged item reflect the use of 10.5 million, 9.7 million and 6.3 million gallons of diesel covered by the fixed price swaps during the years ended December 31, 2014, 2013 and 2012, respectively.

[2] Amounts recognized on derivative represent the effective portion of the fixed price diesel swaps.