EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 144,316	$ 144,625
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	84,889	60,403
Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	59,427	84,222
Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Cash and equivalents [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	26,008	1,370
Cash and equivalents [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	26,008	1,370
Cash and equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Cash and equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Short-term investment funds [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Short-term investment funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Short-term investment funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Short-term investment funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Government agency securities [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Government agency securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Government agency securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Government agency securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Debt instruments [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	14,122	14,291
Debt instruments [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	14,122	14,291
Debt instruments [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Debt instruments [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Equity securities [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	44,759	44,742
Equity securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	44,759	44,742
Equity securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Equity securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Commingled funds [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	53,703	78,490
Commingled funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Commingled funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	53,703	78,490
Commingled funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Limited partnerships and hedge fund investments [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5,724	5,732
Limited partnerships and hedge fund investments [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Limited partnerships and hedge fund investments [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5,724	5,732
Limited partnerships and hedge fund investments [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 0	$ 0