Stock-based Compensation Plans - Summary of Stock Option Activity (Details) (USD $)	3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Stock-Based Compensation Plans [Abstract]
Outstanding at beginning of year (in shares)	87,400	103,700
Options granted (in shares)	0	0
Exercised (in shares)	(10,964)	(2,000)
Outstanding at end of year (in shares)	76,436	101,700
Exercisable at end of year (in shares)	76,436	101,700
Exercised, Weighted Average Exercise Price Per Share (in dollars per share)	$ 12.50	$ 12.50
Outstanding at end of year, Weighted Average Exercise Price Per Share (in dollars per share)	$ 12.50	$ 12.50
Exercisable at end of year, Weighted Average Exercise Price Per Share (in dollars per share)	$ 12.50	$ 12.50