Regulatory Assets and Liabilities and Regulatory Matters (Tables)

12 Months Ended

Sep. 30, 2017

Regulated Operations [Abstract]

Schedule of Regulatory Assets

The following regulatory assets and liabilities are included in our Consolidated Balance Sheets at September 30:

	2017		2016
Regulatory assets:
Income taxes recoverable	$	121,421	$	115,643
Underfunded pension and postretirement plans	141,310		183,129
Environmental costs	61,566		59,397
Deferred fuel and power costs	7,685		151
Removal costs, net	30,996		27,956
Other	5,951		8,865
Total regulatory assets	$	368,929	$	395,141
Regulatory liabilities (a):
Postretirement benefits overcollections	$	17,493	$	17,519
Deferred fuel and power refunds	10,621		22,299
State income tax benefits — distribution system repairs	18,430		15,086
Other	2,686		665
Total regulatory liabilities	$	49,230	$	55,569

(a) Regulatory liabilities, other than deferred fuel and power refunds, are recorded in “Other current liabilities” and “Other noncurrent liabilities” on the Consolidated Balance Sheets.

Schedule of Regulatory Liabilities

The following regulatory assets and liabilities are included in our Consolidated Balance Sheets at September 30:

	2017		2016
Regulatory assets:
Income taxes recoverable	$	121,421	$	115,643
Underfunded pension and postretirement plans	141,310		183,129
Environmental costs	61,566		59,397
Deferred fuel and power costs	7,685		151
Removal costs, net	30,996		27,956
Other	5,951		8,865
Total regulatory assets	$	368,929	$	395,141
Regulatory liabilities (a):
Postretirement benefits overcollections	$	17,493	$	17,519
Deferred fuel and power refunds	10,621		22,299
State income tax benefits — distribution system repairs	18,430		15,086
Other	2,686		665
Total regulatory liabilities	$	49,230	$	55,569

(a) Regulatory liabilities, other than deferred fuel and power refunds, are recorded in “Other current liabilities” and “Other noncurrent liabilities” on the Consolidated Balance Sheets.