Business segment data (Tables)

6 Months Ended

Jun. 30, 2018

Segment Reporting [Abstract]

Information on the Company's businesses

Information on the Company's segments was as follows:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2018			2017			2018			2017
	(In thousands)
External operating revenues:
Regulated operations:
Electric	$	78,499		$	74,574		$	165,904		$	162,799
Natural gas distribution	129,540			131,592			462,204			474,111
Pipeline and midstream	18,645			19,319			23,035			22,190
	226,684			225,485			651,143			659,100
Nonregulated operations:
Pipeline and midstream	5,415			4,520			9,858			8,163
Construction materials and contracting	509,388			501,426			722,672			702,203
Construction services	323,020			336,009			657,071			635,580
Other	90			199			146			519
	837,913			842,154			1,389,747			1,346,465
Total external operating revenues	$	1,064,597		$	1,067,639		$	2,040,890		$	2,005,565
Intersegment operating revenues:
Regulated operations:
Electric	$	—		$	—		$	—		$	—
Natural gas distribution	—			—			—			—
Pipeline and midstream	6,446			6,353			28,182			27,841
	6,446			6,353			28,182			27,841
Nonregulated operations:
Pipeline and midstream	93			59			116			93
Construction materials and contracting	235			172			336			258
Construction services	540			295			550			301
Other	2,667			1,758			5,306			3,501
	3,535			2,284			6,308			4,153
Intersegment eliminations	(9,981		)	(8,637		)	(34,490		)	(31,994		)
Total intersegment operating revenues	$	—		$	—		$	—		$	—

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2018			2017			2018			2017
	(In thousands)
Earnings (loss) on common stock:
Regulated operations:
Electric	$	9,133		$	7,859		$	22,216		$	22,191
Natural gas distribution	(6,852		)	(2,797		)	25,771			25,064
Pipeline and midstream	5,240			5,492			10,699			10,048
	7,521			10,554			58,686			57,303
Nonregulated operations:
Pipeline and midstream	467			(238		)	288			(865		)
Construction materials and contracting	24,336			21,168			815			1,255
Construction services	14,088			12,391			29,179			19,753
Other	(2,337		)	(2,163		)	(2,932		)	(2,440		)
	36,554			31,158			27,350			17,703
Intersegment eliminations*	—			2,093			—			4,266
Earnings on common stock before income (loss) from discontinued operations	44,075			43,805			86,036			79,272
Income (loss) from discontinued operations, net of tax*	(273		)	(3,190		)	203			(1,504		)
Total earnings on common stock	$	43,802		$	40,615		$	86,239		$	77,768

* Includes the eliminations for the presentation of income tax adjustments between continuing and discontinued operations.