Debt (Narrative) (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	1 Months Ended	9 Months Ended
	Mar. 31, 2010	Jun. 30, 2011
Principal amount		$ 287,500,000
Initial conversion price per share		$ 52.35
Net proceeds from Notes		279,000,000
Payment for note hedge		60,100,000
Proceeds from sale of Warrants		26,100,000
Note hedged, shares of common stock covered		5.0
Note hedges, common stock strike price		$ 52.35
Common stock, shares acquired through sale of warrants		5.5
Warrants sold, common stock strike price		73.29
2.50% Senior Convertible Notes Due in 2015 [Member]
Principal amount	287,500,000
Interest rate	2.50%
Maturity date	2015
Convertible conversion rate		19.10
Convertible conversion, principal amount		1,000
Initial conversion price per share		$ 52.35
Percentage repurchase price of principal amount, if fundamental change occurs		100.00%
Note hedges, common stock strike price		$ 52.35
Notes Hedges [Member]
Net proceeds from Notes		$ 34,100,000