CREDIT FACILITIES AND INDEBTEDNESS (Details) - Outstanding Debt (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Mar. 31, 2014	Sep. 30, 2013
Credit facilities	$ 0	$ 0
3.25% Convertible Notes	850.0	850.0
Total principal debt obligations	2,150.0	2,150.0
Discounts:
Discounts	(3.6)	(23.3)
Swap fair value adjustments:
Total outstanding debt, net	2,203.5	2,192.9
7.5% Bonds [Member]
Bonds	500.0	500.0
Discounts:
Discounts	(1.7)	(1.8)
Swap fair value adjustments:
Swap fair value adjustments	42.0	48.4
5.5% Bonds [Member]
Bonds	300.0	300.0
Discounts:
Discounts	(0.9)	(0.9)
Swap fair value adjustments:
Swap fair value adjustments	19.6	22.6
5.35% Bonds [Member]
Bonds	500.0	500.0
Discounts:
Discounts	$ (1.9)	$ (2.1)