Details of Selected Consolidated Balance Sheet Captions

The following tables provide additional information regarding the composition of certain of our balance sheet captions. Assets held for sale at September 30, 2016 are detailed in Note 15.

Accounts receivable

Accounts receivable was comprised of the following at September 30, 2017 and 2016:



	September 30
	2017			2016
	(In thousands)
Billed accounts receivable	$	135,091		$	120,128
Unbilled revenue	73,143			67,396
Other accounts receivable	24,894			39,412
Total accounts receivable	233,128			226,936
Less: allowance for doubtful accounts	(10,865		)	(11,056		)
Net accounts receivable	$	222,263		$	215,880

Other current assets

Other current assets as of September 30, 2017 and 2016 were comprised of the following accounts.



	September 30
	2017		2016
	(In thousands)
Deferred gas costs	$	65,714	$	45,184
Prepaid expenses	32,163		21,489
Taxes receivable	—		5,456
Materials and supplies	4,472		5,825
Assets from risk management activities	2,436		3,029
Other	1,536		7,102
Total	$	106,321	$	88,085

Property, plant and equipment

Property, plant and equipment was comprised of the following as of September 30, 2017 and 2016:



	September 30
	2017			2016
	(In thousands)
Production plant	$	66		$	66
Storage plant	369,510			353,523
Transmission plant	2,521,671			2,232,927
Distribution plant	7,306,021			6,598,990
General plant	765,662			732,606
Intangible plant	38,980			40,515
	11,001,910			9,958,627
Construction in progress	299,394			183,879
	11,301,304			10,142,506
Less: accumulated depreciation and amortization	(2,042,122		)	(1,873,900		)
Net property, plant and equipment⁽¹⁾	$	9,259,182		$	8,268,606


(1)	Net property, plant and equipment includes plant acquisition adjustments of $(64.1) million and $(59.8) million at September 30, 2017 and 2016.

Goodwill

The following presents our goodwill balance allocated by segment and changes in the balance for the fiscal year ended September 30, 2017:



	Distribution		Pipeline and Storage		Total
	(In thousands)
Balance as of September 30, 2016⁽¹⁾	$	583,950	$	143,012	$	726,962
Allocation of goodwill due to disposal of Natural Gas Marketing operations	2,711		—		2,711
Deferred tax adjustments on prior acquisitions⁽²⁾	419		40		459
Balance as of September 30, 2017	$	587,080	$	143,052	$	730,132


(1)	Our discontinued natural gas marketing segment had $16.4 million of goodwill at September 30, 2016. Of this amount, $13.7 million was written off in connection with the sale and the remaining $2.7 million was reallocated to the distribution segment.


(2)	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 $0.5 million for fiscal 2017.

Deferred charges and other assets

Deferred charges and other assets as of September 30, 2017 and 2016 were comprised of the following accounts.



	September 30
	2017		2016
	(In thousands)
Marketable securities	$	88,409	$	72,701
Regulatory assets	110,977		214,890
Assets from risk management activities	803		1,822
Other	20,447		15,606
Total	$	220,636	$	305,019

Accounts payable and accrued liabilities

Accounts payable and accrued liabilities as of September 30, 2017 and 2016 were comprised of the following accounts.



	September 30
	2017		2016
	(In thousands)
Trade accounts payable	$	143,422	$	114,361
Accrued gas payable	50,253		47,107
Accrued liabilities	39,375		35,017
Total	$	233,050	$	196,485

Other current liabilities

Other current liabilities as of September 30, 2017 and 2016 were comprised of the following accounts.



	September 30
	2017		2016
	(In thousands)
Customer credit balances and deposits	$	54,627	$	81,219
Accrued employee costs	46,653		47,058
Deferred gas costs	15,559		20,180
Accrued interest	39,624		34,863
Liabilities from risk management activities	322		56,771
Taxes payable	116,291		104,145
Pension and postretirement obligations	18,411		36,606
Regulatory cost of removal accrual	35,910		52,610
Other	5,251		5,633
Total	$	332,648	$	439,085

Deferred credits and other liabilities

Deferred credits and other liabilities as of September 30, 2017 and 2016 were comprised of the following accounts.



	September 30
	2017		2016
	(In thousands)
Customer advances for construction	$	9,309	$	9,850
Regulatory liabilities	5,257		4,152
Asset retirement obligation	12,827		13,404
Liabilities from risk management activities	112,076		184,048
Other	36,266		33,920
Total	$	175,735	$	245,374