REGULATORY ASSETS AND LIABILITIES (Tables)

6 Months Ended

Jun. 30, 2019

SCHEDULE OF REGULATED ASSETS AND LIABILITIES [Line Items]

SCHEDULE OF REGULATED ASSETS AND LIABILITIES

The tables below present a summary of regulatory assets, net of amortization, and liabilities for the periods indicated:

	June 30, 2019
	Current			Noncurrent			Total
	(Thousands of dollars)
Under-recovered purchased-gas costs	$	767		$	—		$	767
Pension and postemployment benefit costs	22,966			406,441			429,407
Reacquired debt costs	812			6,082			6,894
Ad valorem tax	2,083			—			2,083
MGP remediation costs	98			9,758			9,856
Other	11,646			2,023			13,669
Total regulatory assets, net of amortization	38,372			424,304			462,676
Federal corporate income tax rate changes (a)	(15,755		)	(508,877		)	(524,632		)
Over-recovered purchased-gas costs	(22,616		)	—			(22,616		)
Weather normalization	(8,163		)	—			(8,163		)
Total regulatory liabilities	(46,534		)	(508,877		)	(555,411		)
Net regulatory liabilities	$	(8,162	)	$	(84,573	)	$	(92,735	)

(a) See Note 11 for additional information regarding our federal corporate income tax rate changes to regulatory liabilities.

	December 31, 2018
	Current			Noncurrent			Total
	(Thousands of dollars)
Under-recovered purchased-gas costs	$	25,083		$	—		$	25,083
Pension and postemployment benefit costs	23,384			421,726			445,110
Reacquired debt costs	812			6,487			7,299
MGP remediation costs	—			7,724			7,724
Ad valorem tax	1,070			—			1,070
Other	4,071			1,542			5,613
Total regulatory assets, net of amortization	54,420			437,479			491,899
Federal corporate income tax rate changes (a)	(30,934		)	(520,866		)	(551,800		)
Over-recovered purchased-gas costs	(13,668		)	—			(13,668		)
Weather normalization	(3,792		)	—			(3,792		)
Total regulatory liabilities	(48,394		)	(520,866		)	(569,260		)
Net regulatory assets (liabilities)	$	6,026		$	(83,387	)	$	(77,361	)

(a) See Note 11 for additional information regarding our federal corporate income tax rate changes to regulatory liabilities.