Stockholders' Equity (Narrative) (Details) - $ / shares	3 Months Ended	12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Jun. 30, 2016
Dividends Payable [Line Items]
Cash dividends on common stock (in dollars per share)		$ 1.00	$ 1.00
Anti-dilutive options excluded from calculation of EPS		151,800	113,250
Forecast [Member]
Dividends Payable [Line Items]
Dividend payable, amount per share	$ 0.25
Dividend payable, date to be paid	2017-09
Dividend payable, date of record	Sep. 25, 2017