Marketable Securities

9 Months Ended

Mar. 31, 2012

Marketable Securities [Abstract]

Marketable Securities

4. Marketable Securities

The fair value of the Company's marketable securities was based on quoted market prices or estimates of fair value as of March 31, 2012 and June 30, 2011. The following is a summary of marketable securities, all of which were classified as available-for-sale as of March 31, 2012 and June 30, 2011:

March 31, 2012	Cost		Unrealized Losses			Estimated Fair Value
($ in millions)
Non-current
Municipal auction rate securities	$	6.1	$	(1.0	)	$	5.1
June 30, 2011	Cost		Unrealized Losses			Estimated Fair Value
($ in millions)
Current
Government agency bonds	$	13.7	$	—		$	13.7
Corporate bonds		15.1		—			15.1
Commercial paper		1.7		—			1.7
	$	30.5	$	—		$	30.5
Non-current
Municipal auction rate securities	$	6.1	$	(0.8	)	$	5.3

For the nine months ended March 31, 2012 and 2011, proceeds from sales and maturities of marketable securities were $30.4 million and $157.1 million, respectively.