Note 12 - Credit Facilities and Indebtedness (Detail) - Outstanding Debt (USD $) In Millions, unless otherwise specified												12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Jun. 08, 2010	Dec. 15, 2009	Jun. 15, 2009	Sep. 30, 2012 Convertible Notes [Member]	Sep. 30, 2011 Convertible Notes [Member]	Sep. 30, 2012 Series 1 [Member]	Sep. 30, 2011 Series 1 [Member]	Sep. 30, 2012 Series 2 [Member]	Sep. 30, 2011 Series 2 [Member]	Sep. 30, 2012 Series 1 [Member]	Sep. 30, 2011 Series 1 [Member]	Sep. 30, 2012 Series 2 [Member]	Sep. 30, 2011 Series 2 [Member]	Sep. 30, 2012 Series 1 [Member]	Sep. 30, 2011 Series 1 [Member]	Sep. 30, 2012 Series 2 [Member]	Sep. 30, 2011 Series 2 [Member]
Credit facilities	$ 140.0
3.25% Convertible Notes	850.0	850.0
Bonds																500.0	500.0	300.0	300.0
Total principal debt obligations	1,790.0	1,650.0
Discounts		(2.9)	(1.3)	(43.7)	(2.7)	(60.0)	(93.5)	(2.1)	(2.3)	(1.0)	(1.1)
Swap fair value adjustments												77.0	61.8	42.5	31.4
Total outstanding debt, net	$ 1,846.4	$ 1,646.3