EARNINGS PER COMMON SHARE ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Basic income per common share:
Net income attributable to Pathward Financial, Inc.	$ 23,420	$ 22,391	$ 49,251	$ 61,324	$ 15,903	$ 38,701	$ 59,066	$ 28,037	$ 13,158	$ 18,190	$ 52,304	$ 21,068	$ 156,386	$ 141,708	$ 104,720
Dividends and undistributed earnings allocated to participating securities													(2,565)	(2,698)	(2,414)
Basic net earnings available to common stockholders													153,821	139,010	102,306
Undistributed earnings allocated to nonvested restricted stockholders													2,468	2,575	2,249
Reallocation of undistributed earnings to nonvested restricted stockholders													(2,468)	(2,573)	(2,249)
Diluted net earnings available to common stockholders													$ 153,821	$ 139,012	$ 102,306
Weighted average common shares outstanding (in shares)													29,227,071	31,729,596	34,829,971
Effect of dilutive securities
Total effect of dilutive securities (in shares)													5,176	21,926	0
Total weighted average diluted common shares outstanding (in shares)													29,232,247	31,751,522	34,829,971
Basic earnings per common share (in dollars per share)	$ 0.81	$ 0.76	$ 1.66	$ 2.00	$ 0.50	$ 1.21	$ 1.84	$ 0.84	$ 0.38	$ 0.53	$ 1.45	$ 0.56	$ 5.26	$ 4.38	$ 2.94
Diluted earnings per common share (in dollars per share)	$ 0.81	$ 0.76	$ 1.66	$ 2.00	$ 0.50	$ 1.21	$ 1.84	$ 0.84	$ 0.38	$ 0.53	$ 1.45	$ 0.56	$ 5.26	$ 4.38	$ 2.94
Weighted average shares of nonvested restricted stock, antidilutive (in shares)													487,476	615,811	821,738
Stock options
Effect of dilutive securities
Outstanding options - based upon the two-class method (in shares)													0	0	0
Performance share units
Effect of dilutive securities
Outstanding options - based upon the two-class method (in shares)													5,176	21,926	0