UNCONSOLIDATED AFFILIATES (Tables)

12 Months Ended

Dec. 31, 2018

Schedule of Equity Method Investments [Line Items]

Schedule of Equity Method Investments

Investments in Unconsolidated Affiliates - The following table sets forth our investments in unconsolidated affiliates for the periods indicated:

	Net Ownership Interest	December 31, 2018		December 31, 2017
		(Thousands of dollars)
Northern Border Pipeline	50%	$	381,623	$	396,800
Overland Pass Pipeline Company	50%	429,295		436,111
Roadrunner Gas Transmission	50%	93,857		93,048
Other	Various	64,375		77,197
Investments in unconsolidated affiliates (a)		$	969,150	$	1,003,156

(a) - Equity-method goodwill (Note A) was $38.8 million at December 31, 2018 and 2017.

Equity In Net Earnings From Investments

Schedule of Equity Method Investments [Line Items]

Schedule of Equity Method Investments

Equity in Net Earnings from Investments and Impairments - The following table sets forth our equity in net earnings from investments for the periods indicated:

	Years Ended December 31,
	2018		2017			2016
	(Thousands of dollars)
Northern Border Pipeline	$	67,854	$	68,153		$	69,990
Overland Pass Pipeline Company	65,887		60,067			53,984
Roadrunner Gas Transmission	22,993		19,150			4,445
Other	1,649		11,908			11,271
Equity in net earnings from investments	$	158,383	$	159,278		$	139,690
Impairment of equity investments	$	—	$	(4,270	)	$	—

Unconsolidated Affiliates Financial Information

Schedule of Equity Method Investments [Line Items]

Schedule of Equity Method Investments

Unconsolidated Affiliates Financial Information - The following tables set forth summarized combined financial information of our unconsolidated affiliates for the periods indicated:

	December 31, 2018		December 31, 2017
	(Thousands of dollars)
Balance Sheet
Current assets	$	158,723	$	151,907
Property, plant and equipment, net	$	2,413,662	$	2,490,692
Other noncurrent assets	$	16,273	$	14,793
Current liabilities	$	83,057	$	70,434
Long-term debt	$	480,731	$	479,050
Other noncurrent liabilities	$	47,826	$	53,830
Accumulated other comprehensive loss	$	2,053	$	(9,946	)
Owners’ equity	$	1,974,991	$	2,064,024

	Years Ended December 31,
	2018		2017		2016
	(Thousands of dollars)
Income Statement
Operating revenues	$	637,762	$	639,102	$	578,542
Operating expenses	$	276,373	$	277,121	$	260,753
Net income	$	337,694	$	347,692	$	293,921
Distributions paid to us	$	197,285	$	196,114	$	196,717