FAIR VALUE, Carrying Amounts and Estimated Fair Value of Financial Instruments Not Carried at Fair Value (Details) (Recurring, USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014
Total estimated fair value
Financial assets:
Bank loans, net	$ 11,893,279	$ 10,761,814
Financial liabilities:
Bank deposits	11,275,119	10,028,455
Corporate debt	1,337,388	1,321,270
Carrying amount
Financial assets:
Bank loans, net	11,935,121	10,857,662
Financial liabilities:
Bank deposits	11,272,013	10,028,924
Corporate debt	1,188,916	1,190,836
Quoted prices in active markets for identical assets (Level 1)
Financial assets:
Bank loans, net	0	0
Financial liabilities:
Bank deposits	0	0
Corporate debt	378,700	366,100
Significant other observable inputs (Level 2)
Financial assets:
Bank loans, net	38,848	23,678
Financial liabilities:
Bank deposits	10,921,350	9,684,221
Corporate debt	958,688	955,170
Significant unobservable inputs (level 3)
Financial assets:
Bank loans, net	11,854,431	10,738,136
Financial liabilities:
Bank deposits	353,769	344,234
Corporate debt	$ 0	$ 0