Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Inventories

Inventories

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

	December 31,
	2021		2020
Materials and supplies	$	54,137	$	44,311
Storage gas and fuel	26,477		16,699
Total Inventories	$	80,614	$	61,010

Schedule of Accrued Liabilities

Accrued Expenses

Accrued expenses consisted of the following (in thousands):

	December 31,
	2021		2020
Property taxes	$	86,168	$	89,425
Employee compensation, benefits, and withholdings	44,743		40,538
Customer advances	29,013		16,015
Interest	18,568		18,074
Other (none of which is individually significant)	54,859		43,462
Total Accrued Expenses	$	233,351	$	207,514

Other Noncurrent Liabilities

Other Noncurrent Liabilities

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

	December 31,
	2021		2020
Pension and other employee benefits	$	96,151	$	136,632
Customer advances	80,780		65,186
Future QF obligation, net	64,943		81,379
Asset retirement obligations	38,350		45,355
Environmental	23,395		25,049
Other (none of which is individually significant)	65,700		57,102
Total Noncurrent Liabilities	$	369,319	$	410,703

Supplemental Cash Flow Information

Supplemental Cash Flow Information

	Year Ended December 31,
	2021		2020		2019
			(in thousands)
Cash paid (received) for:
Income taxes	$	4,330	$	115	$	(6,737)
Interest	87,221		84,922		83,776
Significant non-cash transactions:
Capital expenditures included in trade accounts payable	29,034		21,430		33,473
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,
	2021		2020		2019
Cash and cash equivalents	$	2,820	$	5,811	$	5,145
Restricted cash	15,942		11,285		6,925
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	$	18,762	$	17,096	$	12,070