INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2018

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



	Years Ended December 31,
	2018		2017		2016
	(Thousands of dollars)
Current income tax provision
Federal	$	—	$	—	$	(2,016	)
State	289		750		471
Total current income tax provision	289		750		(1,545		)
Deferred income tax provision
Federal	42,413		83,138		76,247
State	10,829		9,255		10,541
Total deferred income tax provision	53,242		92,393		86,788
Total provision for income taxes	$	53,531	$	93,143	$	85,243

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,
	2018			2017			2016
	(Thousands of dollars)
Income before income taxes	$	225,765		$	256,138		$	225,338
Federal statutory income tax rate	21		%	35		%	35		%
Provision for federal income taxes	47,411			89,648			78,868
State income taxes, net of federal tax benefit	8,783			6,503			7,158
Nonregulated deferred tax rate decrease	74			2,162			—
Tax benefit of employee share-based compensation	(2,770		)	(5,162		)	—
Other, net	33			(8		)	(783		)
Total provision for income taxes	$	53,531		$	93,143		$	85,243

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,
	2018		2017
	(Thousands of dollars)
Deferred tax assets
Employee benefits and other accrued liabilities	$	48,243	$	40,277
Regulatory adjustments for enacted tax rate changes	129,201		129,421
Net operating loss	2,778		24,712
Other	34		2,984
Total deferred tax assets	180,256		197,394
Deferred tax liabilities
Excess of tax over book depreciation	717,903		677,249
Purchased-gas cost adjustment	8,981		13,805
Other regulatory assets and liabilities, net	105,798		106,285
Total deferred tax liabilities	832,682		797,339
Net deferred tax liabilities	$	652,426	$	599,945