EMPLOYEE BENEFIT PLANS (Details 3) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Change in plan assets
Fair value of plan assets at beginning of year	$ 108,157	$ 96,818
Fair value of plan assets at end of year	$ 98,060	108,157	$ 96,818
DEFINED CONTRIBUTION PLAN
Percentage of employer's contribution under 401(k)/ Thrift Plan matching the first 5 percent of participant's compensation subject to certain limitations	100.00%
Percentage of participant's compensation eligible for employer's matching contribution	5.00%
Annual expense incurred for defined contribution plan	$ 24,800	32,300	28,300
Oil and Gas Properties
Change in plan assets
Fair value of plan assets at beginning of year	301	287
Unrealized gains (losses) relating to property still held at the reporting date	86	14
Fair value of plan assets at end of year	$ 387	$ 301	$ 287

Actual return on plan assets, separately identifying the amount related to assets still held at the reporting date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)(iv)(02)(A)

-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (c)(iv)(02)(A)

-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2446-114920

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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- Definition

Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Section 35

-Paragraph 50

-URI http://asc.fasb.org/extlink&oid=49178875&loc=d3e12355-114930

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

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- References

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- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

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