Earnings Per Share Attributable to Matthews' Shareholders (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net loss attributable to Matthews shareholders	$ (1,758)	$ (10,466)
Weighted-average shares outstanding [Abstract]
Basic shares (in shares)	31,725	31,136
Effect of dilutive securities (in shares)	0	0
Diluted shares (in shares)	31,725	31,136