Segment Information (Tables)

6 Months Ended

Jun. 30, 2015

Segment Reporting [Abstract]

Schedule of Segment Reporting Information

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

	Natural Gas Operations			Construction Services			Total
Three months ended June 30, 2015
Revenues from external customers	$	286,643		$	229,112		$	515,755
Intersegment revenues		—			22,849			22,849
Total	$	286,643		$	251,961		$	538,604
Segment net income (loss)	$	(657	)	$	5,606		$	4,949
Three months ended June 30, 2014
Revenues from external customers	$	271,479		$	156,966		$	428,445
Intersegment revenues		—			24,708			24,708
Total	$	271,479		$	181,674		$	453,153
Segment net income	$	1,798		$	7,829		$	9,627
	Natural Gas Operations			Construction Services			Total
Six months ended June 30, 2015
Revenues from external customers	$	839,758		$	390,201		$	1,229,959
Intersegment revenues		—			42,865			42,865
Total	$	839,758		$	433,066		$	1,272,824
Segment net income (loss)	$	78,264		$	(1,332	)	$	76,932
Six months ended June 30, 2014
Revenues from external customers	$	757,972		$	255,119		$	1,013,091
Intersegment revenues		—			48,458			48,458
Total	$	757,972		$	303,577		$	1,061,549
Segment net income	$	74,397		$	6,013		$	80,410
	Natural Gas Operations			Construction Services			Total
Twelve months ended June 30, 2015
Revenues from external customers	$	1,463,873		$	782,514		$	2,246,387
Intersegment revenues		—			86,595			86,595
Total	$	1,463,873		$	869,109		$	2,332,982
Segment net income	$	120,739		$	16,909		$	137,648
Twelve months ended June 30, 2014
Revenues from external customers	$	1,325,657		$	562,294		$	1,887,951
Intersegment revenues		—			99,301			99,301
Total	$	1,325,657		$	661,595		$	1,987,252
Segment net income	$	117,310		$	17,539		$	134,849