Auction Rate Securities (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Auction Rate Securities Fair Value (Textual) [Abstract]
Auction Rate Securities with fair value maturing from 2015 to 2017	$ 9,500,000		$ 9,500,000
Auction Rate Securities with fair value maturing from 2040 to 2045	6,400,000		6,400,000
ARS investments, investment grade	11,100,000		11,100,000
ARS investments, below investment grade	18,500,000		18,500,000
Contractual maturity of ARS investment			Greater than five years
Minimum Period of Auction Rate Securities investment in which unrealized loss			12 Months
Scenario, Forecast [Member]
Auction Rate Securities (Textual) [Abstract]
Auction rate securities with fair value having no stated maturity	2,100,000		2,100,000
Auction Rate Securities [Member]
Auction Rate Securities (Textual) [Abstract]
ARS investments redeemed at discount from par	5,700,000		7,900,000
ARS investments redeemed at par		$ 100,000		$ 350,000