Marketable Securities (Tables)

3 Months Ended

Sep. 30, 2011

Marketable Securities [Abstract]

Summary Of Marketable Securities Classified As Available-For-Sale Securities

		$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