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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, SALES TAX ACCOUNTING (Details) - USD ($) $ in Millions | 12 Months Ended
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Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2014
Accounting Policies [Abstract] |  |  |  |
Sales tax |  | $ 31.0 | $ 44.1 | $ 47.4
TEFA | [1] | 0.0 | 0.0 | 1.4
Total |  | $ 31.0 | $ 44.1 | $ 48.8
[1] | TEFA was phased out in January 2014.

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