INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2021

Income tax [Line Items]

Reconciliation of Income Tax Provision

The following table sets forth our provision for income taxes for the periods indicated:

	Years Ended December 31,
	2021		2020		2019
	(Thousands of dollars)
Current income tax provision (benefit)
Federal	$	(1,568)	$	20,129	$	24,537
State	(1,565)		2,965		5,008
Total current income tax provision (benefit)	(3,133)		23,094		29,545
Deferred income tax provision
Federal	37,810		10,757		8,375
State	5,639		7,728		4,932
Total deferred income tax provision	43,449		18,485		13,307
Total provision for income taxes	$	40,316	$	41,579	$	42,852

Schedule of Effective Income Tax Rate Reconciliation

The following table is a reconciliation of our income tax provision for the periods indicated:

	Years Ended December 31,
	2021			2020			2019
	(Thousands of dollars)
Income before income taxes	$	246,750		$	237,991		$	229,601
Federal statutory income tax rate	21		%	21		%	21		%
Provision for federal income taxes	51,817			49,978			48,215
State income taxes, net of federal tax benefit	4,074			10,693			9,758
Amortization of EDIT regulatory liability	(17,289)			(17,031)			(12,828)
Tax benefit of employee share-based compensation	(469)			(1,489)			(2,116)
Other, net	2,183			(572)			(177)
Total provision for income taxes	$	40,316		$	41,579		$	42,852

Schedule of Deferred Tax Assets and Liabilities

The following table sets forth the tax effects of temporary differences that gave rise to significant portions of the deferred tax assets and liabilities for the periods indicated:

	December 31,
	2021		2020
	(Thousands of dollars)
Deferred tax assets
Employee benefits and other accrued liabilities	$	11,126	$	28,127
Regulatory adjustments for enacted tax rate changes	120,051		121,738
Net operating loss	424,861		—
Lease obligation basis	6,906		9,319
Other	12,597		4,790
Total deferred tax assets	575,541		163,974
Deferred tax liabilities
Excess of tax over book depreciation	734,051		717,492
Winter weather event costs	421,070		—
Purchased-gas cost adjustment - other	37,433		5,240
Other regulatory assets and liabilities, net	71,541		88,260
Right-of-use asset basis	6,730		9,788
Total deferred tax liabilities	1,270,825		820,780
Net deferred tax liabilities	$	695,284	$	656,806