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

		$30.5		$30.5			$30.5
September 30, 2011 ($ in millions)	Cost		Unrealized Losses			Estimated Fair Value

Non-current
Municipal auction rate securities	$	6.1	$	(1.0	)	$	5.1

		$30.5		$30.5			$30.5
June 30, 2011 ($ in millions)	Cost		Unrealized Losses			Estimated Fair Value
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 three months ended September 30, 2011 and 2010, proceeds from sales and maturities of marketable securities were $30.4 million and $89.8 million, respectively.