EMPLOYEE BENEFIT PLANS (Details 3) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Change in plan assets
Fair value of plan assets at beginning of year	$ 96,818,000	$ 86,718,000
Fair value of plan assets at end of year	108,157,000	96,818,000	86,718,000
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	32,300,000	28,300,000	26,700,000
Oil and Gas Properties
Change in plan assets
Fair value of plan assets at beginning of year	287,000	299,000
Unrealized gains (losses) relating to property still held at the reporting date	14,000	(12,000)
Fair value of plan assets at end of year	$ 301,000	$ 287,000