Stockholders' Equity (Details) (USD $)	1 Months Ended	3 Months Ended					6 Months Ended
	Jul. 25, 2012	Mar. 31, 2013	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2013	Mar. 31, 2012
Stockholders' Equity [Abstract]
Amount of stock repurchase authorization	$ 100,000,000
Amount remaining under stock repurchase authorization		100,000,000
Cash dividends declared per common share (in dollars per share)		$ 0.0000	$ 0.0375	$ 0.0375	$ 0.0375	$ 0.0375	$ 0.1875	$ 0.0750
Debt Conversion, Converted Instrument, Shares Issued			76.5697				77.18004
Incremental Common Shares Attributable to Conversion of Debt Securities		38,600,000			0		38,600,000	0
Dividend Declared [Member]
Stockholders' Equity [Abstract]
Cash dividends declared per common share (in dollars per share)							$ 0.0375
Accelerated Dividend [Member]
Stockholders' Equity [Abstract]
Cash dividends declared per common share (in dollars per share)							$ 0.15
2% convertible senior notes [Member]
Stockholders' Equity [Abstract]
Principal amount		$ 1,000					$ 1,000
Debt Instrument, Convertible, Conversion Price		$ 12.96	$ 13.06				$ 12.96