Revenue from contracts with customers (Tables)

9 Months Ended

Sep. 30, 2018

Revenue from Contract with Customer [Abstract]

Disaggregation of revenue

For more information on the Company's business segments, see Note 14.

Three Months Ended September 30, 2018	Electric		Natural gas distribution		Pipeline and midstream			Construction materials and contracting			Construction services			Other			Total
	(in thousands)
Residential utility sales	$	31,424	$	43,825	$	—		$	—		$	—		$	—		$	75,249
Commercial utility sales	36,259		28,174		—			—			—			—			64,433
Industrial utility sales	8,738		4,421		—			—			—			—			13,159
Other utility sales	2,056		—		—			—			—			—			2,056
Natural gas transportation	—		10,841		21,400			—			—			—			32,241
Natural gas gathering	—		—		2,320			—			—			—			2,320
Natural gas storage	—		—		2,795			—			—			—			2,795
Contracting services	—		—		—			409,006			—			—			409,006
Construction materials	—		—		—			538,962			—			—			538,962
Intrasegment eliminations*	—		—		—			(204,040		)	—			—			(204,040		)
Inside specialty contracting	—		—		—			—			217,474			—			217,474
Outside specialty contracting	—		—		—			—			100,988			—			100,988
Other	6,158		3,208		5,701			—			15			3,084			18,166
Intersegment eliminations	—		—		(3,187		)	(165		)	(782		)	(3,037		)	(7,171		)
Revenues from contracts with customers	84,635		90,469		29,029			743,763			317,695			47			1,265,638
Revenues out of scope	1,445		1,779		42			—			11,883			—			15,149
Total external operating revenues	$	86,080	$	92,248	$	29,071		$	743,763		$	329,578		$	47		$	1,280,787

* Intrasegment revenues are presented within the construction materials and contracting segment to highlight the focus on vertical integration as this segment sells materials to both third parties and internal customers. Due to consolidation requirements, these revenues must be eliminated against construction materials to arrive at the external operating revenue total for the segment.

Nine Months Ended September 30, 2018	Electric		Natural gas distribution		Pipeline and midstream			Construction materials and contracting			Construction services			Other			Total
	(in thousands)
Residential utility sales	$	93,359	$	305,399	$	—		$	—		$	—		$	—		$	398,758
Commercial utility sales	103,636		185,885		—			—			—			—			289,521
Industrial utility sales	25,734		17,457		—			—			—			—			43,191
Other utility sales	5,766		—		—			—			—			—			5,766
Natural gas transportation	—		32,104		64,505			—			—			—			96,609
Natural gas gathering	—		—		6,900			—			—			—			6,900
Natural gas storage	—		—		8,563			—			—			—			8,563
Contracting services	—		—		—			730,628			—			—			730,628
Construction materials	—		—		—			1,100,185			—			—			1,100,185
Intrasegment eliminations*	—		—		—			(363,877		)	—			—			(363,877		)
Inside specialty contracting	—		—		—			—			667,664			—			667,664
Outside specialty contracting	—		—		—			—			283,432			—			283,432
Other	22,836		10,821		13,353			—			32			8,536			55,578
Intersegment eliminations	—		—		(31,485		)	(501		)	(1,332		)	(8,343		)	(41,661		)
Revenues from contracts with customers	251,331		551,666		61,836			1,466,435			949,796			193			3,281,257
Revenues out of scope	653		2,786		129			—			36,853			—			40,421
Total external operating revenues	$	251,984	$	554,452	$	61,965		$	1,466,435		$	986,649		$	193		$	3,321,678

* Intrasegment revenues are presented within the construction materials and contracting segment to highlight the focus on vertical integration as this segment sells materials to both third parties and internal customers. Due to consolidation requirements, these revenues must be eliminated against construction materials to arrive at the external operating revenue total for the segment.

Contract balances

The changes in contract assets and liabilities were as follows:

	September 30, 2018			December 31, 2017			Change			Location on Consolidated Balance Sheets
	(In thousands)
Contract assets	$	142,376		$	109,540		$	32,836		Receivables, net
Contract liabilities - current	(98,470		)	(84,123		)	(14,347		)	Accounts payable
Contract liabilities - noncurrent	(399		)	—			(399		)	Deferred credits and other liabilities - other
Net contract assets	$	43,507		$	25,417		$	18,090