Stock Rights Plan (Details)	12 Months Ended
	Jun. 30, 2017 $ / shares shares
Stock Rights Plan [Abstract]
Expiration date of the plan	Dec. 31, 2019
Number of rights distributed as a dividend, per share of common stock	1
Date purchased rights distributed	Apr. 14, 1989
Number of shares that can be purchased by exercising each stock right	0.50
Exercise price (per share) | $ / shares	$ 25
Beneficial ownership percentage that causes rights to be exercisable	15.00%
Percentage sale of assets or earning power to another person where rights become exercisable	50.00%