CONSOLIDATED STATEMENTS OF INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Sales	$ 1,795,737	$ 1,880,896	$ 1,762,403
Cost of sales	(1,266,030)	(1,303,224)	(1,240,125)
Gross profit	529,707	577,672	522,278
Selling expense	(141,875)	(140,119)	(128,362)
Administrative expense	(346,405)	(307,368)	(298,315)
Intangible amortization	(37,023)	(42,068)	(57,084)
Goodwill write-downs	(16,727)	0	(82,454)
Operating (loss) profit	(12,323)	88,117	(43,937)
Interest expense	(50,534)	(44,648)	(27,725)
Other income (deductions), net	(6,800)	(2,559)	(32,557)
(Loss) income before income taxes	(69,657)	40,910	(104,219)
Income tax benefit (provision)	9,997	(1,774)	4,391
Net (loss) income	(59,660)	39,136	(99,828)
Net loss attributable to noncontrolling interests	0	155	54
Net (loss) income attributable to Matthews shareholders	$ (59,660)	$ 39,291	$ (99,774)
(Loss) earnings per share attributable to Matthews shareholders:
Basic (in dollars per share)	$ (1.93)	$ 1.28	$ (3.18)
Diluted (in dollars per share)	$ (1.93)	$ 1.26	$ (3.18)