Credit Arrangements (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Mar. 31, 2013
Credit agreement capacity	$ 15.0
Interest rate over LIBOR	1.00%
Interest rate under prime rate	1.00%
Line of Credit Facility, Remaining Borrowing Capacity	12.7
Assets Held-in-trust	6.9
Letters Of Credit [Member]
Credit agreement capacity	5.0
Line of Credit Facility, Amount Outstanding	2.3
Unsecured [Member]
Credit agreement capacity	$ 8.0