Share Repurchase Program - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
	Mar. 31, 2012	Mar. 31, 2012
Equity, Class of Treasury Stock [Line Items]
Authorization to repurchase common shares	Under the program, the Company is authorized to repurchase an amount of common shares each fiscal year equal to the greater of 7.5 million shares or five percent of the shares outstanding as of the end of the prior fiscal year.
Authorization to repurchase common shares, percentage of shares of common stock outstanding at the end of the prior fiscal year	5.00%
Shares repurchased	235,046	4,850,573
Average price per share, including commissions	$ 85.09	$ 68.44
Maximum
Equity, Class of Treasury Stock [Line Items]
Authorization to repurchase common shares, number of shares	7,500,000	7,500,000