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, 2016 and 2015:



	September 30
	2016			2015
	(In thousands)
Billed accounts receivable	$	120,128		$	120,482
Unbilled revenue	67,396			65,008
Other accounts receivable	39,412			40,777
Total accounts receivable	226,936			226,267
Less: allowance for doubtful accounts	(11,056		)	(12,934		)
Net accounts receivable	$	215,880		$	213,333

Other current assets

Other current assets as of September 30, 2016 and 2015 were comprised of the following accounts.



	September 30
	2016		2015
	(In thousands)
Assets from risk management activities	$	3,029	$	378
Deferred gas costs	45,184		9,715
Taxes receivable	5,456		4,479
Prepaid expenses	21,489		21,654
Materials and supplies	5,825		12,587
Other	7,102		1,116
Total	$	88,085	$	49,929

Property, plant and equipment

Property, plant and equipment was comprised of the following as of September 30, 2016 and 2015:



	September 30
	2016			2015
	(In thousands)
Production plant	$	66		$	131
Storage plant	353,523			286,011
Transmission plant	2,232,927			1,844,117
Distribution plant	6,598,990			6,019,001
General plant	732,606			740,863
Intangible plant	40,515			41,131
	9,958,627			8,931,254
Construction in progress	183,879			280,421
	10,142,506			9,211,675
Less: accumulated depreciation and amortization	(1,873,900		)	(1,794,975		)
Net property, plant and equipment⁽¹⁾	$	8,268,606		$	7,416,700


⁽¹⁾	Net property, plant and equipment includes plant acquisition adjustments of $(59.8) million and $(68.1) million at September 30, 2016 and 2015.

Goodwill

The following presents our goodwill balance allocated by segment and changes in the balance for the fiscal year ended September 30, 2016:



	Distribution		Pipeline and Storage		Total
	(In thousands)
Balance as of September 30, 2015⁽²⁾	$	583,285	$	142,972	$	726,257
Deferred tax adjustments on prior acquisitions⁽¹⁾	665		40		705
Balance as of September 30, 2016⁽²⁾	$	583,950	$	143,012	$	726,962


⁽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 2016.


⁽²⁾	Natural gas marketing had goodwill of $16.4 million at September 30, 2016 and 2015 classified as assets held for sale on the consolidated balance sheet.

Deferred charges and other assets

Deferred charges and other assets as of September 30, 2016 and 2015 were comprised of the following accounts.



	September 30
	2016		2015
	(In thousands)
Marketable securities	$	72,701	$	74,200
Regulatory assets	214,890		182,573
Assets from risk management activities	1,822		368
Other	15,606		18,283
Total	$	305,019	$	275,424

Accounts payable and accrued liabilities

Accounts payable and accrued liabilities as of September 30, 2016 and 2015 were comprised of the following accounts.

Other current liabilities

Other current liabilities as of September 30, 2016 and 2015 were comprised of the following accounts.



	September 30
	2016		2015
	(In thousands)
Customer credit balances and deposits	$	81,219	$	99,043
Accrued employee costs	47,058		47,602
Deferred gas costs	20,180		28,100
Accrued interest	34,863		34,914
Liabilities from risk management activities	56,771		9,568
Taxes payable	104,145		92,912
Pension and postretirement obligations	36,606		21,857
Current deferred tax liability	—		55,918
Regulatory cost of removal accrual	52,610		56,123
Other	5,633		1,653
Total	$	439,085	$	447,690

Deferred credits and other liabilities

Deferred credits and other liabilities as of September 30, 2016 and 2015 were comprised of the following accounts.



	September 30
	2016		2015
	(In thousands)
Customer advances for construction	$	9,850	$	9,316
Regulatory liabilities	4,152		3,693
Asset retirement obligation	13,404		9,063
Liabilities from risk management activities	184,048		110,539
Other	33,920		28,738
Total	$	245,374	$	161,349