Quarterly Financial Data (Unaudited) - Summary of Quarterly Operating Data (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Interest income													$ 107,052	$ 97,482	$ 77,174
Interest expense													26,916	24,700	14,791
Net interest expense													80,136	72,782	62,383
Provision for loan losses													6,002	2,032	3,047
Noninterest income													14,750	13,093	12,369
Noninterest expense													54,452	47,892	42,973
Income tax expense													6,887	7,047	7,803
NET INCOME													$ 27,545	$ 28,904	$ 20,929
Quarterly Operating Data
Interest income	$ 27,264	$ 26,220	$ 26,646	$ 26,922	$ 26,047	$ 25,186	$ 24,207	$ 22,042	$ 20,147	$ 19,385	$ 19,231	$ 18,411
Interest expense	5,483	6,802	7,269	7,362	7,054	6,632	6,139	4,875	4,245	3,710	3,528	3,308
Net interest expense	21,781	19,418	19,377	19,560	18,993	18,554	18,068	17,167	15,902	15,675	15,703	15,103
Provision for loan losses	1,868	2,850	388	896	545	491	314	682	987	550	642	868
Noninterest income	4,358	3,229	3,674	3,489	3,158	3,423	3,568	2,944	3,134	3,506	2,811	2,918
Noninterest expense	15,509	13,569	13,025	12,349	12,196	12,667	12,066	10,963	10,852	11,563	10,156	10,402
Income before income taxes	8,762	6,228	9,638	9,804	9,410	8,819	9,256	8,466	7,197	7,068	7,716	6,751
Income tax expense	1,861	1,129	1,921	1,976	1,854	1,725	1,802	1,666	1,558	1,810	2,546	1,889
NET INCOME	$ 6,901	$ 5,099	$ 7,717	$ 7,828	$ 7,556	$ 7,094	$ 7,454	$ 6,800	$ 5,639	$ 5,258	$ 5,170	$ 4,862