Benefit Plans - Schedule of Impact of Retrospective Application to Consolidated Statement of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Miscellaneous non-interest expense:
Miscellaneous	$ 3,425	$ 2,862	$ 10,257	$ 8,051
Salaries and employee benefits:
Salaries and employee benefits	$ 15,350	12,814	$ 46,691	38,458
As Previously Reported [Member]
Miscellaneous non-interest expense:
Miscellaneous		2,788		7,828
Salaries and employee benefits:
Salaries and employee benefits		12,888		38,681
As Reported Under the New Guidance [Member]
Miscellaneous non-interest expense:
Miscellaneous		2,862		8,051
Salaries and employee benefits:
Salaries and employee benefits		$ 12,814		$ 38,458