EMPLOYEE BENEFIT PLANS (Details) - Plan assets and benefit obligation of the defined benefit plans - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Change in benefit obligation:
Actuarial (gain) loss	$ (887)
Change in plan assets:
Fair value of plan assets at beginning of fiscal year	150,822
Fair value of plan assets at end of fiscal year	150,634	$ 150,822
Pension Plan [Member]
Change in benefit obligation:
Benefit obligation at beginning of fiscal year	174,337	189,156
Interest cost	5,084	4,892	$ 5,465
Benefits paid	(10,531)	(10,393)
Actuarial (gain) loss	(7,562)	(9,318)
Benefit obligation at end of fiscal year	161,328	174,337	189,156
Change in plan assets:
Fair value of plan assets at beginning of fiscal year	150,822	144,316
Actual return on plan assets	7,940	13,152
Company contributions	2,449	3,747
Benefits paid	(10,531)	(10,393)
Fair value of plan assets at end of fiscal year	150,680	150,822	144,316
Projected benefit obligation in excess of plan assets	10,648	23,515
Amounts recognized in the statement of financial position consist of:
Accrued liabilities	0	0
Other liabilities (long-term)	(10,648)	(23,515)
Total Liabilities	(10,648)	(23,515)
Net actuarial losses	19,088	24,608
Prior service cost	0	0
Deferred taxes	(6,103)	(9,069)
Total Accumulated other comprehensive loss, net of tax	12,985	15,539
Net amount recognized at September 30,	2,337	(7,976)
Accumulated benefit obligations	161,328	174,337
Information for plans with accumulated benefit obligations in excess of plan assets:
ABO	161,328	174,337
PBO	(10,648)	(23,515)
Fair value of plan assets	150,680	150,822
Supplemental Employee Retirement Plan [Member]
Change in benefit obligation:
Benefit obligation at beginning of fiscal year	32,627	35,774
Interest cost	544	715	1,243
Benefits paid	(3,001)	(4,057)
Actuarial (gain) loss	(14,452)	195
Benefit obligation at end of fiscal year	15,718	32,627	35,774
Change in plan assets:
Fair value of plan assets at beginning of fiscal year	0	0
Actual return on plan assets	0	0
Company contributions	3,001	4,057
Benefits paid	(3,001)	(4,057)
Fair value of plan assets at end of fiscal year	0	0	$ 0
Projected benefit obligation in excess of plan assets	15,718	32,627
Amounts recognized in the statement of financial position consist of:
Accrued liabilities	(1,906)	(3,984)
Other liabilities (long-term)	(13,812)	(28,643)
Total Liabilities	(15,718)	(32,627)
Net actuarial losses	4,965	20,045
Prior service cost	28	42
Deferred taxes	(1,597)	(7,486)
Total Accumulated other comprehensive loss, net of tax	3,396	12,601
Net amount recognized at September 30,	(12,322)	(20,026)
Accumulated benefit obligations	15,718	32,627
Information for plans with accumulated benefit obligations in excess of plan assets:
ABO	15,718	32,627
PBO	(15,718)	(32,627)
Fair value of plan assets	$ 0	$ 0