PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS Part 1 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Pension Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost - benefits earned during the period	$ 2,311	$ 2,312
Interest cost	4,066	4,871
Expected return on plan assets	(4,741)	(4,899)
Amortization of prior service cost (credit)	136	148
Amortization of actuarial loss	2,839	2,277
Sub-total	4,611	4,709
Regulatory adjustment	(434)	(483)
Net benefit cost	4,177	4,226
Postretirement Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost - benefits earned during the period	2,533	2,015
Interest cost	1,279	1,380
Expected return on plan assets	(1,081)	(991)
Amortization of transition obligation	23	34
Amortization of prior service cost (credit)	1	(518)
Amortization of actuarial loss	1,325	1,065
Sub-total	4,080	2,985
Regulatory adjustment	(1,699)	(604)
Net benefit cost	$ 2,381	$ 2,381