Summary of Signficant Accounting Policies (Table)

12 Months Ended

Sep. 30, 2012

Accumulated Other Comprehensive Income Loss Table [Abstract]

Accumulated other comprehensive income/loss table

	September 30
	2012		2011
	(In thousands)
Unrealized holding gains on investments	$	5,661	$	2,558
Treasury lock agreements		(44,273)		(34,157)
Cash flow hedges		(8,995)		(16,861)
	$	(47,607)	$	(48,460)

Regulatory Assets And Liabilities Table [Abstract]

Regulatory assets and liabilities table

		September 30
		2012		2011
			(In thousands)
Regulatory assets:
	Pension and postretirement benefit costs	$	296,160	$	254,666
	Merger and integration costs, net		5,754		6,242
	Deferred gas costs		31,359		33,976
	Regulatory cost of removal asset		10,500		8,852
	Rate case costs		4,661		4,862
	Deferred franchise fees		2,714		379
	Risk-based replacement program costs		5,370		-
	APT annual adjustment mechanism		4,539		-
	Other		7,262		3,919
		$	368,319	$	312,896
Regulatory liabilities:
	Deferred gas costs	$	23,072	$	8,130
	Regulatory cost of removal obligation		459,688		464,025
	APT annual adjustment mechanism		-		6,654
	Other		5,637		7,371
		$	488,397	$	486,180