FAIR VALUE - DEBT (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Sep. 30, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Capital leases		$ 48,200	$ 46,900
Level 2 [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	[1]	807,845	807,845
Level 2 [Member] | Fair Market Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value		$ 832,202	$ 817,319

[1] Excludes capital leases of $48.2 million and $46.9 million as of March 31, 2016 and September 30, 2015, respectively.