Segment Information (Tables)

9 Months Ended

Sep. 30, 2018

Segment Reporting [Abstract]

Schedule of Segment Reporting Information

The following tables present revenues from external customers, intersegment revenues, and segment net income for the two reportable segments (thousands of dollars):

	Natural Gas Operations			Infrastructure Services		Other			Total
Three Months Ended September 30, 2018
Revenues from external customers	$	217,523		$	414,175	$	—		$	631,698
Intersegment revenues	—			36,448		—			36,448
Total	$	217,523		$	450,623	$	—		$	668,146
Segment net income (loss)	$	(13,670	)	$	26,798	$	(797	)	$	12,331
Three Months Ended September 30, 2017
Revenues from external customers	$	213,059		$	351,850	$	—		$	564,909
Intersegment revenues	—			28,244		—			28,244
Total	$	213,059		$	380,094	$	—		$	593,153
Segment net income (loss)	$	(4,024	)	$	14,335	$	(107	)	$	10,204
	Natural Gas Operations			Infrastructure Services		Other			Total
Nine Months Ended September 30, 2018
Revenues from external customers	$	987,515		$	1,009,166	$	—		$	1,996,681
Intersegment revenues	—			96,678		—			96,678
Total	$	987,515		$	1,105,844	$	—		$	2,093,359
Segment net income (loss)	$	79,301		$	35,034	$	(1,362	)	$	112,973
Nine Months Ended September 30, 2017
Revenues from external customers	$	935,823		$	800,073	$	—		$	1,735,896
Intersegment revenues	—			72,463		—			72,463
Total	$	935,823		$	872,536	$	—		$	1,808,359
Segment net income (loss)	$	82,436		$	15,717	$	(777	)	$	97,376
	Natural Gas Operations			Infrastructure Services		Other			Total
Twelve Months Ended September 30, 2018
Revenues from external customers	$	1,354,000		$	1,358,418	$	—		$	2,712,418
Intersegment revenues	—			121,374		—			121,374
Total	$	1,354,000		$	1,479,792	$	—		$	2,833,792
Segment net income (loss)	$	153,683		$	57,677	$	(1,922	)	$	209,438
Twelve Months Ended September 30, 2017
Revenues from external customers	$	1,276,308		$	1,078,195	$	—		$	2,354,503
Intersegment revenues	—			95,381		—			95,381
Total	$	1,276,308		$	1,173,576	$	—		$	2,449,884
Segment net income (loss)	$	134,323		$	29,010	$	(777	)	$	162,556