COMMITMENTS AND CONTINGENT LIABILITIES, CAPITAL EXPENDITURES (Details) (USD $)	9 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Long-term Purchase Commitment [Line Items]
Payments to Acquire Other Productive Assets	$ 17,529,000	$ 0
Minimum [Member] | Solar Related Expenditures [Member]
Long-term Purchase Commitment [Line Items]
Estimated Capital Expenditures	70,000,000
Maximum [Member] | Solar Related Expenditures [Member]
Long-term Purchase Commitment [Line Items]
Estimated Capital Expenditures	80,000,000
Solar Related Expenditures [Member]
Long-term Purchase Commitment [Line Items]
Estimated Capital Expenditures Subsequent Fiscal Year	65,600,000
Capital Expenditures Paid and Committed	77,600,000
Payments to Acquire Other Productive Assets	19,500,000
Solar Related Expenditures Land Only [Member]
Long-term Purchase Commitment [Line Items]
Payments to Acquire Other Productive Assets	2,000,000
Gas Distribution [Member]
Long-term Purchase Commitment [Line Items]
Estimated Capital Expenditures	108,200,000
Estimated Capital Expenditures Subsequent Fiscal Year	116,100,000
Capital Expenditures Paid And Accrued	76,100,000
AIP I Construction Costs [Member]
Long-term Purchase Commitment [Line Items]
Estimated Capital Expenditures	26,000,000
Capital Expenditures Paid And Accrued	24,900,000
AIP II Construction Costs [Member]
Long-term Purchase Commitment [Line Items]
Estimated Capital Expenditures	11,000,000
Capital Expenditures Paid And Accrued	789,000
Maximum [Member]
Long-term Purchase Commitment [Line Items]
Operating Leases, Future Minimum Payments Due, Current	2,100,000
Operating Leases, Future Minimum Payments, Due in Two Years	2,100,000
Operating Leases, Future Minimum Payments, Due in Three Years	2,100,000
Operating Leases, Future Minimum Payments, Due in Four Years	2,100,000
Operating Leases, Future Minimum Payments, Due in Five Years	2,100,000
Operating Leases, Future Minimum Payments, Due Thereafter	$ 1,300,000