Goodwill and Purchased Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended					12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Jul. 02, 2012 JLG	Jul. 02, 2012 Pierce	Sep. 30, 2012 Access Equipment	Sep. 30, 2011 Access Equipment	Sep. 30, 2012 Fire and Emergency	Sep. 30, 2011 Fire and Emergency	Sep. 30, 2012 Commercial	Sep. 30, 2011 Commercial
Goodwill and Intangible Assets Disclosure [Abstract]
Minimum weighted-average cost of capital (as a percent)	13.00%
Maximum weighted-average cost of capital (as a percent)	15.00%
Terminal growth rate (as a percent)	3.00%
Changes in goodwill
Net goodwill at the beginning of the period	$ 1,041.5	$ 1,049.6				$ 912.2	$ 916.0	$ 107.9	$ 112.2	$ 21.4	$ 21.4
Impairment		(4.3)	(16.8)				0		(4.3)		0
Foreign currency translation	(5.9)	(3.7)				(6.1)	(3.8)	0	0.1	0.2	0
Other	(1.8)	(0.1)				0	0	(1.8)	(0.1)	0	0
Net goodwill at the end of the period	1,033.8	1,041.5	1,049.6			906.1	912.2	106.1	107.9	21.6	21.4
Details of the Company's goodwill allocated to the reportable segments
Gross	2,150.0	2,223.7				1,838.2	1,844.3	114.3	182.1	197.5	197.3
Accumulated Impairment	(1,116.2)	(1,182.2)				(932.1)	(932.1)	(8.2)	(74.2)	(175.9)	(175.9)
Net	$ 1,033.8	$ 1,041.5	$ 1,049.6			$ 906.1	$ 912.2	$ 106.1	$ 107.9	$ 21.6	$ 21.4
Percentage of recorded goodwill and purchased intangibles concentrated within the JLG reporting unit in the access equipment segment (as a percent)				88.00%	7.00%