Income Taxes (Reconciliation Of The Effective Income Tax Rate) (Details)	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%	28.10%	35.00%
State and local income taxes	3.10%	3.50%	3.00%
Net windfall tax benefits - stock-based compensation	(0.80%)	(0.80%)	(0.40%)
ESOP dividend deduction	(0.10%)	(0.10%)	(0.10%)
One-time benefit on re-measurement of net deferred tax liability	0.00%	0.00%	(5.50%)
Domestic manufacturing deduction for qualified income	0.00%	0.00%	(2.30%)
Other	0.30%	(0.60%)	(0.50%)
Effective rate	23.50%	23.00%	22.30%