CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Net revenue	$ 2,673.8	$ 3,182.8	$ 2,826.0
Cost of goods sold	1,773.0	2,126.3	1,877.8
Gross profit	900.8	1,056.5	948.2
Selling, general and administrative expenses	650.0	713.6	574.1
Amortization expense	94.3	102.4	79.6
Impairment charges	83.5	265.0	0.0
Gain on sale of property, plant, and equipment	0.0	36.0	0.0
Gain on equity method investments	(74.6)	(5.8)	(0.1)
Pension settlement (gain) charges	1.7	(35.2)	0.0
Loss on divestiture	57.2	0.0	0.0
Interest expense, net	94.5	121.5	77.7
(Loss) income from continuing operations before income taxes	(2.4)	(139.4)	216.9
Income tax (benefit) expense	(54.5)	64.8	102.8
Income (loss) from continuing operations	52.1	(204.2)	114.1
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	0.0	2.2	19.5
Supplemental Income Statement Elements [Abstract]
Income from discontinued operations (net of income tax (benefit) expense)	0.0	2.2	462.6
Gain on divestiture of discontinued operations (net of income tax expense)	0.0	0.0	443.1
Consolidated net income (loss)	52.1	(202.0)	576.7
Less: Net income attributable to noncontrolling interests	9.0	9.0	7.0
Net income (loss) attributable to Hillenbrand	$ 43.1	$ (211.0)	$ 569.7
Net income - per share of common stock:
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.61	$ (3.03)	$ 1.53
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0	0.03	6.63
Basic (loss) earnings per share (in dollars per share)	0.61	(3.00)	8.16
Income (Loss) from Continuing Operations, Per Diluted Share	0.61	(3.03)	1.53
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	0	0.03	6.60
Diluted (loss) earnings per share (in dollars per share)	$ 0.61	$ (3.00)	$ 8.13
Weighted-average shares outstanding-basic (in shares)	70.7	70.4	69.8
Weighted-average shares outstanding-diluted (in shares)	70.8	70.4	70.1