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, 2015 and 2014:



	September 30
	2015			2014
	(In thousands)
Billed accounts receivable	$	204,585		$	262,937
Unbilled revenue	65,008			62,484
Other accounts receivable	40,850			41,971
Total accounts receivable	310,443			367,392
Less: allowance for doubtful accounts	(15,283		)	(23,992		)
Net accounts receivable	$	295,160		$	343,400

Other current assets

Other current assets as of September 30, 2015 and 2014 were comprised of the following accounts.



	September 30
	2015		2014
	(In thousands)
Assets from risk management activities	$	9,232	$	45,827
Deferred gas costs	9,715		20,069
Taxes receivable	4,479		5,481
Prepaid expenses	27,734		25,039
Materials and supplies	12,587		5,704
Other	6,822		9,145
Total	$	70,569	$	111,265

Property, plant and equipment

Property, plant and equipment was comprised of the following as of September 30, 2015 and 2014:



	September 30
	2015			2014
	(In thousands)
Production plant	$	131		$	4,821
Storage plant	286,011			275,579
Transmission plant	1,844,117			1,622,846
Distribution plant	6,019,001			5,522,794
General plant	769,311			735,223
Intangible plant	41,131			38,858
	8,959,702			8,200,121
Construction in progress	280,398			247,579
	9,240,100			8,447,700
Less: accumulated depreciation and amortization	(1,809,520		)	(1,721,794		)
Net property, plant and equipment⁽¹⁾	$	7,430,580		$	6,725,906


⁽¹⁾	Net property, plant and equipment includes plant acquisition adjustments of $(68.1) million and $(76.4) million at September 30, 2015 and 2014.

Goodwill

The following presents our goodwill balance allocated by segment and changes in the balance for the fiscal year ended September 30, 2015:



	Regulated Distribution		Regulated Pipeline		Nonregulated		Total
	(In thousands)
Balance as of September 30, 2014	$	574,816	$	132,502	$	34,711	$	742,029
Deferred tax adjustments on prior acquisitions⁽¹⁾	633		40		—		673
Balance as of September 30, 2015	$	575,449	$	132,542	$	34,711	$	742,702


⁽¹⁾	We annually adjust 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 for fiscal 2015.

Deferred charges and other assets

Deferred charges and other assets as of September 30, 2015 and 2014 were comprised of the following accounts.



	September 30
	2015		2014
	(In thousands)
Marketable securities	$	74,200	$	79,613
Regulatory assets	182,573		230,240
Deferred financing costs	17,873		13,698
Assets from risk management activities	368		13,038
Other	13,664		14,340
Total	$	288,678	$	350,929

Accounts payable and accrued liabilities

Accounts payable and accrued liabilities as of September 30, 2015 and 2014 were comprised of the following accounts.

Other current liabilities

Other current liabilities as of September 30, 2015 and 2014 were comprised of the following accounts.



	September 30
	2015		2014
	(In thousands)
Customer credit balances and deposits	$	100,232	$	82,085
Accrued employee costs	47,602		46,445
Deferred gas costs	28,100		35,063
Accrued interest	34,914		36,768
Liabilities from risk management activities	9,568		1,730
Taxes payable	93,674		77,601
Pension and postretirement obligations	21,857		11,380
Current deferred tax liability	55,918		48,751
Regulatory cost of removal accrual	56,123		45,061
Other	9,966		20,985
Total	$	457,954	$	405,869

Deferred credits and other liabilities

Deferred credits and other liabilities as of September 30, 2015 and 2014 were comprised of the following accounts.



	September 30
	2015		2014
	(In thousands)
Customer advances for construction	$	9,316	$	9,883
Regulatory liabilities	3,693		4,472
Asset retirement obligation	9,063		10,508
Liabilities from risk management activities	110,539		20,126
Other	29,085		23,881
Total	$	161,696	$	68,870