CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	MSB Financial Corporation [Member]	Cumulative Effect Period Of Adoption Adjustment [Member]	Common Stock [Member]	Common Stock [Member] MSB Financial Corporation [Member]	Paid-in Capital [Member]	Paid-in Capital [Member] MSB Financial Corporation [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect Period Of Adoption Adjustment [Member]	Unearned ESOP Shares [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance (in value) at Jun. 30, 2019	$ 1,127,159			$ 891		$ 787,394		$ 366,679		$ (30,644)	$ 2,839
Balance (in shares) at Jun. 30, 2019				89,126,000
Net Income	22,022							22,022
Other comprehensive income (loss), net of income tax	5,116										5,116
ESOP shares committed to be released	1,353					380				973
Stock option expense	917					917
Share repurchases (in value)	(52,254)			$ (39)		(52,215)
Stock repurchases (in shares)				(3,900,000)
Restricted stock plan shares earned (in value)	1,999					1,999
Cancellation of shares issued for restricted stock awards (in value)	(937)			$ (1)		(936)
Cancellation of shares issued for restricted stock awards (in shares)				(76,000)
Cash dividends declared	(10,805)							(10,805)
Balance (in value) at Dec. 31, 2019	1,094,570			$ 851		737,539		377,896		(29,671)	7,955
Balance (in shares) at Dec. 31, 2019				85,150,000
Balance (in value) at Sep. 30, 2019	1,110,789			$ 868		758,385		373,004		(30,158)	8,690
Balance (in shares) at Sep. 30, 2019				86,786,000
Net Income	10,652							10,652
Other comprehensive income (loss), net of income tax	(735)										(735)
ESOP shares committed to be released	694					207				487
Stock option expense	466					466
Share repurchases (in value)	(21,672)			$ (16)		(21,656)
Stock repurchases (in shares)				(1,574,000)
Restricted stock plan shares earned (in value)	1,014					1,014
Cancellation of shares issued for restricted stock awards (in value)	(878)			$ (1)		(877)
Cancellation of shares issued for restricted stock awards (in shares)				(62,000)
Cash dividends declared	(5,760)							(5,760)
Balance (in value) at Dec. 31, 2019	1,094,570			$ 851		737,539		377,896		(29,671)	7,955
Balance (in shares) at Dec. 31, 2019				85,150,000
Balance (in value) at Jun. 30, 2020	$ 1,084,177			$ 837		722,871		387,911		(28,699)	1,257
Balance (in shares) at Jun. 30, 2020	83,663,192			83,663,000
Cumulative effect of change in accounting principle for the adoption of ASU 2017-08 at Jun. 30, 2020			$ (14,239)						$ (14,239)
Balance - July 1, 2020 as adjusted for change in accounting principle at Jun. 30, 2020	$ 1,069,938			$ 837		722,871		373,672		(28,699)	1,257
Net Income	28,327							28,327
Other comprehensive income (loss), net of income tax	5,196										5,196
ESOP shares committed to be released	861					(112)				973
Stock option expense	911					911
Share repurchases (in value)	(45,704)			$ (45)		(45,659)
Stock repurchases (in shares)				(4,509,000)
Restricted stock plan shares earned (in value)	1,991					1,991
Cancellation of shares issued for restricted stock awards (in value)	(689)			$ (1)		(688)
Cancellation of shares issued for restricted stock awards (in shares)				(70,000)
Acquisition of MSB Financial Corp (in value)		$ 45,133			$ 58		$ 45,075
Acquisition of MSB Financial Corp (in shares)					5,854,000
Cash dividends declared	(13,623)							(13,623)
Balance (in value) at Dec. 31, 2020	$ 1,092,341			$ 849		724,389		388,376		(27,726)	6,453
Balance (in shares) at Dec. 31, 2020	84,938,272			84,938,000
Balance (in value) at Sep. 30, 2020	$ 1,124,060			$ 895		769,269		378,134		(28,212)	3,974
Balance (in shares) at Sep. 30, 2020				89,510,000
Net Income	16,948							16,948
Other comprehensive income (loss), net of income tax	2,479										2,479
ESOP shares committed to be released	474					(12)				486
Stock option expense	455					455
Share repurchases (in value)	(45,704)			$ (45)		(45,659)
Stock repurchases (in shares)				(4,509)
Restricted stock plan shares earned (in value)	975					975
Cancellation of shares issued for restricted stock awards (in value)	(640)			$ (1)		(639)
Cancellation of shares issued for restricted stock awards (in shares)				(63,000)
Cash dividends declared	(6,706)							(6,706)
Balance (in value) at Dec. 31, 2020	$ 1,092,341			$ 849		$ 724,389		$ 388,376		$ (27,726)	$ 6,453
Balance (in shares) at Dec. 31, 2020	84,938,272			84,938,000