Earnings Per Share - Narrative (Details) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended	9 Months Ended		3 Months Ended						3 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Sep. 30, 2011	Mar. 31, 2012 Common Stock	Jun. 30, 2012 Convertible Subordinated Debt	Sep. 30, 2011 Convertible Subordinated Debt	Jun. 30, 2012 Senior Notes	Sep. 30, 2011 Senior Notes	Jun. 30, 2012 Tangible Equity Units	Mar. 31, 2012 7 1/2% Mandatory Convertible Subordinated Notes [Member] Convertible Subordinated Debt	Jun. 30, 2012 7 1/2% Mandatory Convertible Subordinated Notes [Member] Convertible Subordinated Debt	Mar. 31, 2012 Tangible Equity Units Senior Notes TEUs	May 31, 2010 Tangible Equity Units Senior Notes TEUs	Jun. 30, 2012 Amortizing Notes Senior Notes	Sep. 30, 2011 Amortizing Notes Senior Notes
Earnings Per Share [Line Items]
Weighted average number of shares outstanding related to Convertible Debt and Tangible Equity Units		9.7
Debt Conversion, Converted Instrument, Shares Issued				11.0
Value of convertible debt exchanged for common stock										$ 48,100,000
Shares exchanged for common stock				13.8
Tangible Equity Units (TEUs) issued during period, (units)												2,800,000	3,000,000
Long-term debt	1,442,407,000	1,442,407,000	1,488,826,000		9,402,000	57,500,000	1,125,377,000	1,132,152,000			9,400,000
Tangible Equity Units outstanding									0.2
Senior notes														$ 392,000	$ 10,062,000
Shares of common stock issuable upon conversion	2.8