Separate Financial Information of Subsidiary Guarantors of Indebtedness (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Condensed Consolidating Statements of Income
Net sales	$ 1,524.3	$ 1,554.2	$ 2,776.3	$ 2,907.5
Cost of sales	1,265.0	1,278.4	2,334.2	2,402.0
Gross income	259.3	275.8	442.1	505.5
Selling, general and administrative	154.7	152.8	294.0	303.3
Amortization of purchased intangibles	13.2	13.3	26.4	26.8
Operating income	91.4	109.7	121.7	175.4
Interest expense	(15.6)	(28.8)	(30.2)	(43.2)
Interest income	0.5	0.6	1.0	1.4
Miscellaneous, net	(1.0)	1.3	(1.0)	0.0
Income before income taxes and equity in earnings of unconsolidated affiliates	75.3	82.8	91.5	133.6
Provision for income taxes	20.3	29.5	22.0	45.7
Income before equity in earnings of unconsolidated affiliates	55.0	53.3	69.5	87.9
Income (Loss) from Equity Method Investments of Consolidated Subsidiaries	0.0	0.0	0.0	0.0
Equity in earnings of unconsolidated affiliates	1.1	1.3	1.2	1.4
Net income	56.1	54.6	70.7	89.3
Net income	56.1	54.6	70.7	89.3
Other Comprehensive Income (Loss), Net of Tax	19.1	(52.6)	8.6	(75.7)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	75.2	2.0	79.3	13.6
Oshkosh Corporation
Condensed Consolidating Statements of Income
Net sales	0.0	0.0	0.0	0.0
Cost of sales	0.4	0.3	0.7	0.3
Gross income	(0.4)	(0.3)	(0.7)	(0.3)
Selling, general and administrative	35.0	28.1	58.6	59.9
Amortization of purchased intangibles	0.0	0.0	0.0	0.0
Operating income	(35.4)	(28.4)	(59.3)	(60.2)
Interest expense	(70.4)	(74.6)	(130.0)	(132.4)
Interest income	0.4	0.4	0.9	0.9
Miscellaneous, net	13.6	10.0	28.5	18.2
Income before income taxes and equity in earnings of unconsolidated affiliates	(91.8)	(92.6)	(159.9)	(173.5)
Provision for income taxes	(34.1)	(29.0)	(39.9)	(57.6)
Income before equity in earnings of unconsolidated affiliates	(57.7)	(63.6)	(120.0)	(115.9)
Income (Loss) from Equity Method Investments of Consolidated Subsidiaries	113.8	118.2	191.0	205.2
Equity in earnings of unconsolidated affiliates	0.0	0.0	(0.3)	0.0
Net income	56.1	54.6	70.7	89.3
Other Comprehensive Income (Loss), Net of Tax	19.1	(52.6)	8.6	(75.7)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	75.2	2.0	79.3	13.6
Guarantor Subsidiaries
Condensed Consolidating Statements of Income
Net sales	1,284.0	1,298.5	2,340.8	2,456.9
Cost of sales	1,071.0	1,087.7	1,970.0	2,054.5
Gross income	213.0	210.8	370.8	402.4
Selling, general and administrative	96.9	99.3	186.2	191.4
Amortization of purchased intangibles	9.7	9.9	19.5	19.7
Operating income	106.4	101.6	165.1	191.3
Interest expense	(16.2)	(13.1)	(30.9)	(25.9)
Interest income	23.1	16.0	39.3	31.3
Miscellaneous, net	(50.5)	(5.7)	(91.9)	(69.0)
Income before income taxes and equity in earnings of unconsolidated affiliates	62.8	98.8	81.6	127.7
Provision for income taxes	18.8	32.0	20.4	44.0
Income before equity in earnings of unconsolidated affiliates	44.0	66.8	61.2	83.7
Income (Loss) from Equity Method Investments of Consolidated Subsidiaries	36.0	17.7	54.1	53.5
Equity in earnings of unconsolidated affiliates	0.0	0.0	0.0	0.0
Net income	80.0	84.5	115.3	137.2
Other Comprehensive Income (Loss), Net of Tax	0.7	(1.5)	(2.2)	(4.2)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	80.7	83.0	113.1	133.0
Non-Guarantor Subsidiaries
Condensed Consolidating Statements of Income
Net sales	269.4	277.9	489.8	492.7
Cost of sales	222.8	212.3	417.9	389.3
Gross income	46.6	65.6	71.9	103.4
Selling, general and administrative	22.8	25.4	49.2	52.0
Amortization of purchased intangibles	3.5	3.4	6.9	7.1
Operating income	20.3	36.8	15.8	44.3
Interest expense	(0.4)	(0.4)	(1.1)	(0.9)
Interest income	48.4	43.5	92.6	85.2
Miscellaneous, net	35.9	(3.0)	62.4	50.8
Income before income taxes and equity in earnings of unconsolidated affiliates	104.2	76.9	169.7	179.4
Provision for income taxes	35.6	26.6	41.5	59.3
Income before equity in earnings of unconsolidated affiliates	68.6	50.3	128.2	120.1
Income (Loss) from Equity Method Investments of Consolidated Subsidiaries	19.6	72.1	13.2	84.6
Equity in earnings of unconsolidated affiliates	1.1	1.3	1.5	1.4
Net income	89.3	123.7	142.9	206.1
Other Comprehensive Income (Loss), Net of Tax	18.0	(42.1)	9.9	(71.9)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	107.3	81.6	152.8	134.2
Eliminations
Condensed Consolidating Statements of Income
Net sales	(29.1)	(22.2)	(54.3)	(42.1)
Cost of sales	(29.2)	(21.9)	(54.4)	(42.1)
Gross income	0.1	(0.3)	0.1	0.0
Selling, general and administrative	0.0	0.0	0.0	0.0
Amortization of purchased intangibles	0.0	0.0	0.0	0.0
Operating income	0.1	(0.3)	0.1	0.0
Interest expense	71.4	59.3	131.8	116.0
Interest income	(71.4)	(59.3)	(131.8)	(116.0)
Miscellaneous, net	0.0	0.0	0.0	0.0
Income before income taxes and equity in earnings of unconsolidated affiliates	0.1	(0.3)	0.1	0.0
Provision for income taxes	0.0	(0.1)	0.0	0.0
Income before equity in earnings of unconsolidated affiliates	0.1	(0.2)	0.1	0.0
Income (Loss) from Equity Method Investments of Consolidated Subsidiaries	(169.4)	(208.0)	(258.3)	(343.3)
Equity in earnings of unconsolidated affiliates	0.0	0.0	0.0	0.0
Net income	(169.3)	(208.2)	(258.2)	(343.3)
Other Comprehensive Income (Loss), Net of Tax	(18.7)	43.6	(7.7)	76.1
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ (188.0)	$ (164.6)	$ (265.9)	$ (267.2)