Details of Selected Consolidated Balance Sheet Captions

The following tables provide additional information regarding the composition of certain of our balance sheet captions.

Accounts receivable

Accounts receivable was comprised of the following at September 30, 2013 and 2012:



	September 30
	2013			2012
	(In thousands)
Billed accounts receivable	$	230,712		$	177,953
Unbilled revenue	58,710			42,694
Other accounts receivable	33,194			23,304
Total accounts receivable	322,616			243,951
Less: allowance for doubtful accounts	(20,624		)	(9,425		)
Net accounts receivable	$	301,992		$	234,526

Other current assets

Other current assets as of September 30, 2013 and 2012 were comprised of the following accounts.



	September 30
	2013		2012
	(In thousands)
Assets from risk management activities	$	18,099	$	24,707
Deferred gas costs	15,152		31,359
Taxes receivable	3,141		1,291
Current deferred tax asset	—		27,091
Prepaid expenses	21,666		17,114
Materials and supplies	5,511		5,872
Assets held for sale⁽¹⁾	—		154,571
Other	6,765		10,777
Total	$	70,334	$	272,782

⁽¹⁾As discussed in Note 16, assets and liabilities related to our Georgia operations were classified as “assets held for sale” in other current assets and liabilities in our consolidated balance sheets at September 30, 2012.

Property, plant and equipment

Property, plant and equipment was comprised of the following as of September 30, 2013 and 2012:



	September 30
	2013			2012
	(In thousands)
Production plant	$	5,020		$	5,020
Storage plant	262,246			232,260
Transmission plant	1,362,662			1,185,007
Distribution plant	5,061,711			4,680,877
General plant	716,189			717,568
Intangible plant	38,444			39,626
	7,446,272			6,860,358
Construction in progress	275,747			274,112
	7,722,019			7,134,470
Less: accumulated depreciation and amortization	(1,691,364		)	(1,658,866		)
Net property, plant and equipment⁽¹⁾	$	6,030,655		$	5,475,604


⁽¹⁾	Net property, plant and equipment includes plant acquisition adjustments of ($83.8) million and ($91.5) million at September 30, 2013 and 2012.

Goodwill

The following presents our goodwill balance allocated by segment and changes in the balance for the fiscal year ended September 30, 2013:



	Natural Gas Distribution		Regulated Transmission and Storage		Nonregulated		Total
	(In thousands)
Balance as of September 30, 2012	$	573,550	$	132,422	$	34,711	$	740,683
Deferred tax adjustments on prior acquisitions⁽¹⁾	640		40		—		680
Balance as of September 30, 2013	$	574,190	$	132,462	$	34,711	$	741,363


⁽¹⁾	During the preparation of the fiscal 2013 tax provision, we adjusted certain deferred taxes recorded in connection with acquisitions completed in fiscal 2001 and fiscal 2004, which resulted in an increase to goodwill and net deferred tax liabilities of $0.7 million.

Deferred charges and other assets

Deferred charges and other assets as of September 30, 2013 and 2012 were comprised of the following accounts.



	September 30
	2013		2012
	(In thousands)
Marketable securities	$	72,682	$	64,398
Regulatory assets	273,287		358,495
Deferred financing costs	15,199		11,157
Assets from risk management activities	109,354		2,283
Other	14,474		14,929
Total	$	484,996	$	451,262

Accounts payable and accrued liabilities

Accounts payable and accrued liabilities as of September 30, 2013 and 2012 were comprised of the following accounts.



	September 30
	2013		2012
	(In thousands)
Trade accounts payable	$	70,116	$	82,531
Accrued gas payable	121,202		81,658
Accrued liabilities	50,293		51,040
Total	$	241,611	$	215,229

Other current liabilities

Other current liabilities as of September 30, 2013 and 2012 were comprised of the following accounts.



	September 30
	2013		2012
	(In thousands)
Customer credit balances and deposits	$	76,313	$	100,926
Accrued employee costs	54,034		37,675
Deferred gas costs	16,481		23,072
Accrued interest	36,744		34,451
Liabilities from risk management activities	1,543		85,381
Taxes payable	66,960		64,319
Pension and postretirement obligations	22,940		39,625
Current deferred tax liability	14,697		—
Regulatory cost of removal accrual	68,225		78,525
Liabilities held for sale	—		11,573
Other	10,954		14,118
Total	$	368,891	$	489,665

Deferred credits and other liabilities

Deferred credits and other liabilities as of September 30, 2013 and 2012 were comprised of the following accounts.



	September 30
	2013		2012
	(In thousands)
Customer advances for construction	$	11,723	$	12,937
Regulatory liabilities	1,123		5,638
Asset retirement obligation	6,764		10,394
Liabilities from risk management activities	6,133		9,206
Other	17,953		12,555
Total	$	43,696	$	50,730