Shareholders' Equity (Narrative) (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended	6 Months Ended	9 Months Ended
	Oct. 26, 2011	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2012	Jun. 30, 2012
Preferred stock, shares outstanding		0	0	0	0
Preferred stock, shares authorized		5,000,000	5,000,000	5,000,000	5,000,000
Preferred stock, par value		$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized		200,000,000	200,000,000	200,000,000	200,000,000
Common stock, par value		$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock, shares issued		96,848,238	96,848,238	96,848,238	96,132,542
Treasury stock, shares		28,992,092	28,992,092	28,992,092	28,846,226
Common stock, shares outstanding		67,856,146	67,856,146	67,856,146	67,286,316
Board of Directors authorized the repurchase of common stock	$ 200
Repurchased shares under the buyback program		15,900	145,866	3,392,275
Cost of repurchased shares under buyback program		0.6	5.4	129.3
Expiry date of share buyback program		Oct. 25, 2013	Oct. 25, 2013	Oct. 25, 2013
Investments included in other current assets		$ 1.9	$ 1.9	$ 1.9	$ 1.8