UNCONSOLIDATED AFFILIATES

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



	Net Ownership Interest	December 31, 2017		December 31, 2016
		(Thousands of dollars)
Northern Border Pipeline	50%	$	396,800	$	328,456
Overland Pass Pipeline Company	50%	436,111		444,138
Roadrunner Gas Transmission	50%	93,048		94,548
Other	Various	77,197		91,665
Investments in unconsolidated affiliates (a)		$	1,003,156	$	958,807

(a) - Equity-method goodwill (Note A) was $38.8 million and $40.1 million at December 31, 2017 and 2016, respectively.

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,
	2017			2016		2015
	(Thousands of dollars)
Northern Border Pipeline	$	68,153		$	69,990	$	66,941
Overland Pass Pipeline Company	60,067			53,984		37,783
Roadrunner Gas Transmission	19,150			4,445		1,800
Other	11,908			11,271		18,776
Equity in net earnings from investments	$	159,278		$	139,690	$	125,300
Impairment of equity investments	$	(4,270	)	$	—	$	(180,583	)

Impairment Charges - In the third quarter 2017, following a review of nonstrategic assets for potential divestiture, we recorded $4.3 million of noncash impairment charges related to a nonstrategic equity investment located in Oklahoma, which was later sold.

In 2015, due to the continued and greater than expected decline in volumes gathered in the dry natural gas area of the Powder River Basin and our decision to cease operations of our wholly owned coal-bed methane natural gas gathering system in 2016, we recorded noncash impairment charges of $180.6 million in 2015 related to our Bighorn Gas Gathering, Fort Union Gas Gathering and Lost Creek Gathering Company equity investments.

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



	December 31, 2017			December 31, 2016
	(Thousands of dollars)
Balance Sheet
Current assets	$	151,907		$	143,317
Property, plant and equipment, net	$	2,490,692		$	2,579,607
Other noncurrent assets	$	14,793		$	20,784
Current liabilities	$	70,434		$	77,388
Long-term debt	$	479,050		$	649,539
Other noncurrent liabilities	$	53,830		$	69,265
Accumulated other comprehensive loss	$	(9,946	)	$	(7,450	)
Owners’ equity	$	2,064,024		$	1,954,966



	Years Ended December 31,
	2017		2016		2015
	(Thousands of dollars)
Income Statement
Operating revenues	$	639,102	$	578,542	$	524,496
Operating expenses (a)	$	277,121	$	260,753	$	304,930
Net income (a)	$	347,692	$	293,921	$	200,064

Distributions paid to us	$	196,114	$	196,717	$	155,918

(a) Includes long-lived asset impairment charges in 2015.

We incurred expenses in transactions with unconsolidated affiliates of $156.1 million, $140.3 million and $104.7 million for 2017, 2016 and 2015, respectively, primarily related to Overland Pass Pipeline Company and Northern Border Pipeline. Accounts payable to our equity-method investees at December 31, 2017 and 2016, was $13.6 million and $11.1 million, respectively.

Northern Border Pipeline - The Northern Border Pipeline partnership agreement provides that distributions to Northern Border Pipeline’s partners are to be made on a pro rata basis according to each partner’s percentage interest. The Northern Border Pipeline Management Committee determines the amount and timing of such distributions. Any changes to, or suspension of, the cash distribution policy of Northern Border Pipeline requires the unanimous approval of the Northern Border Pipeline Management Committee. Cash distributions are equal to 100 percent of distributable cash flow as determined from Northern Border Pipeline’s financial statements based upon EBITDA less interest expense and maintenance capital expenditures. Loans or other advances from Northern Border Pipeline to its partners or affiliates are prohibited under its credit agreement. In 2017, we made an equity contribution of $83 million to Northern Border Pipeline.

Under the terms of settlement with shippers in 2012, Northern Border Pipeline was required to file a rate case by January 1, 2018. In December 2017, Northern Border Pipeline entered into a settlement with shippers that was approved by the FERC in February 2018. The settlement provides for tiered rate reductions beginning January 1, 2018, that will reduce rates 12.5 percent by January 2020 compared with previous rates and requires new rates to be established by January 2024. We do not expect the resulting decrease in equity earnings and cash distributions from Northern Border Pipeline to be material to us.

Overland Pass Pipeline Company - The Overland Pass Pipeline Company limited liability company agreement provides that distributions to Overland Pass Pipeline Company’s members are to be made on a pro rata basis according to each member’s percentage interest. The Overland Pass Pipeline Company Management Committee determines the amount and timing of such distributions. Any changes to, or suspension of, the cash distributions from Overland Pass Pipeline Company requires the unanimous approval of the Overland Pass Pipeline Management Committee. Cash distributions are equal to 100 percent of available cash as defined in the limited liability company agreement.

Roadrunner Gas Transmission - In March 2015, we entered into a 50-50 joint venture with a subsidiary of Fermaca, a Mexico City-based natural gas infrastructure company, to construct the Roadrunner pipeline to transport natural gas from the Permian Basin in West Texas to the Mexican border near El Paso, Texas. We contributed $4 million and $65 million to Roadrunner in 2017 and 2016, respectively.

The Roadrunner limited liability company agreement provides that distributions to members are made on a pro rata basis according to each member’s ownership interest. As the operator, we have been delegated the authority to determine such distributions in accordance with, and on the frequency set forth in, the Roadrunner limited liability company agreement. Cash distributions are equal to 100 percent of available cash, as defined in the limited liability company agreement.

We have an operating agreement with Roadrunner that provides for reimbursement or payment to us for management services and certain operating costs. Reimbursements and payments from Roadrunner included in operating income in our Consolidated Statements of Income for the years ended December 31, 2017, 2016 and 2015, were not material.