EMPLOYEE BENEFIT PLANS, FAIR VALUE (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2011
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	$ 200,236	[1]	$ 166,664	[1]	$ 124,289	[1]
Pension [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	200,236		166,664
Pension [Member] | Money Market Funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	3		0
Pension [Member] | Large Cap Index Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	69,707		55,006
Pension [Member] | Small Cap Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	14,736		9,988
Pension [Member] | World Equity ES-Us Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	42,792		34,266
Pension [Member] | Emerging Markets Debt Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	8,754		8,380
Pension [Member] | High Yield Bond Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	19,850		16,635
Pension [Member] | Long Duration Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	44,394		42,389
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	49,555		41,090		31,428
OPEB [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	49,555		41,090
OPEB [Member] | Money Market Funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	1,150		1,159
OPEB [Member] | Large Cap Index Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	16,419		13,217
OPEB [Member] | Small Cap Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	3,444		2,380
OPEB [Member] | World Equity ES-Us Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	10,033		8,166
OPEB [Member] | Emerging Markets Debt Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	11,684		10,207
OPEB [Member] | High Yield Bond Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	2,163		1,997
OPEB [Member] | Long Duration Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets	$ 4,662		$ 3,964

[1] Includes the Company's PEP.