Note 10 - Credit Facilities and Indebtedness (Detail) - Total Outstanding debt (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Mar. 31, 2013	Sep. 30, 2012
Principal Debt Obligations	$ 1,770.0	$ 1,790.0
Total outstanding debt, net	1,829.3	1,846.4
7.5% Bonds [Member]
Swap Fair Value Adjustments	67.7	77.0
5.5% Bonds [Member]
Swap Fair Value Adjustments	36.5	42.5
3.25% Convertible Notes [Member]
Discounts	(42.0)	(60.0)
7.5% Bonds [Member]
Discounts	(1.9)	(2.1)
5.5% Bonds [Member]
Discounts	(1.0)	(1.0)
Credit Facilities [Member]
Principal Debt Obligations	120.0	140.0
3.25% Convertible Notes [Member]
Principal Debt Obligations	850.0	850.0
7.5% Bonds [Member]
Principal Debt Obligations	500.0	500.0
5.5% Bonds [Member]
Principal Debt Obligations	$ 300.0	$ 300.0