Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Inventories

Inventories

Inventories are stated at average cost. Inventory consisted of the following (in thousands):

	December 31,
	2022		2021
Materials and supplies	$	71,769	$	54,137
Storage gas and fuel	35,590		26,477
Total Inventories	$	107,359	$	80,614

Schedule of Accrued Liabilities

Accrued Expenses and other

Accrued expenses and other consisted of the following (in thousands):

	December 31,
	2022		2021
Property taxes	$	96,093	$	86,168
Employee compensation, benefits, and withholdings	44,104		44,743
Customer advances	26,137		29,013
Interest	18,350		18,568
Other (none of which is individually significant)	65,895		54,859
Total Accrued Expenses	$	250,579	$	233,351

Other Noncurrent Liabilities

Other Noncurrent Liabilities

Other noncurrent liabilities consisted of the following (in thousands):

	December 31,
	2022		2021
Pension and other employee benefits	$	84,731	$	96,151
Customer advances	95,393		80,780
Future QF obligation, net	49,728		64,943
Asset retirement obligations	39,096		38,350
Environmental	22,662		23,395
Other (none of which is individually significant)	63,793		65,700
Total Noncurrent Liabilities	$	355,403	$	369,319

Supplemental Cash Flow Information

Supplemental Cash Flow Information

	Year Ended December 31,
	2022		2021		2020
			(in thousands)
Cash paid for:
Income taxes	$	4,707	$	4,330	$	115
Interest	95,400		87,221		84,922
Significant non-cash transactions:
Capital expenditures included in trade accounts payable	64,758		29,034		21,430
NMTC debt extinguishment included in other noncurrent assets(1)	—		18,169		—
NMTC debt extinguishment included in property, plant and equipment, net(1)	—		6,594		—
NMTC debt extinguishment included in long-term debt(1)	—		1,259		—

Reconciliation of Cash and Restricted Cash [Table Text Block]

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows (in thousands):

	December 31,
	2022		2021		2020
Cash and cash equivalents	$	8,489	$	2,820	$	5,811
Restricted cash	13,974		15,942		11,285
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	$	22,463	$	18,762	$	17,096