Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2019

Amounts representing balances billed but not paid by customers under retainage provisions in contracts at December 31 were as follows:



	2019		2018
	(In thousands)
Short-term retainage*	$	75,590	$	56,228
Long-term retainage**	14,228		4,152
Total retainage	$	89,818	$	60,380


*	Expected to be paid within one year or less and included in receivables, net.

Included in deferred charges and other assets - other.

Inventories

Inventories at December 31 consisted of:



	2019		2018
	(In thousands)
Aggregates held for resale	$	147,723	$	139,681
Asphalt oil	41,912		54,741
Materials and supplies	22,512		23,611
Merchandise for resale	22,232		22,552
Natural gas in storage (current)	22,058		22,117
Other	21,970		24,607
Total	$	278,407	$	287,309

AFUDC and interest capitailized

The amount of AFUDC for the years ended December 31 were as follows:



	2019		2018		2017
	(In thousands)
AFUDC - borrowed	$	2,807	$	2,290	$	966
AFUDC - equity	$	698	$	1,897	$	909

Property, plant and equipment

Property, plant and equipment at December 31 was as follows:



	2019		2018		Weighted Average Depreciable Life in Years
	(Dollars in thousands, where applicable)
Regulated:
Electric:
Generation	$	1,139,059	$	1,131,484	48
Distribution	443,780		430,750		46
Transmission	445,485		302,315		65
Construction in progress	66,664		161,893		—
Other	132,157		122,127		15
Natural gas distribution:
Distribution	2,133,249		1,981,356		47
Construction in progress	39,506		21,028		—
Other	515,368		496,708		17
Pipeline and midstream:
Transmission	636,796		585,594		46
Gathering	35,661		37,829		20
Storage	50,001		49,101		53
Construction in progress	22,597		5,915		—
Other	48,340		45,763		16
Nonregulated:
Pipeline and midstream:
Gathering and processing	31,148		31,094		19
Construction in progress	154		86		—
Other	9,518		9,577		10
Construction materials and contracting:
Land	127,729		109,541		—
Buildings and improvements	122,064		114,905		20
Machinery, vehicles and equipment	1,180,343		1,090,790		12
Construction in progress	25,018		22,507		—
Aggregate reserves	455,408		430,263		*
Construction services:
Land	7,146		5,216		—
Buildings and improvements	31,735		29,795		24
Machinery, vehicles and equipment	156,537		145,859		6
Other	17,952		7,716		2
Other:
Land	2,648		2,648		—
Other	32,565		25,461		14
Less accumulated depreciation, depletion and amortization	2,991,486		2,818,644
Net property, plant and equipment	$	4,917,142	$	4,578,677


*	Depleted on the units-of-production method based on recoverable aggregate reserves.

Schedule of earnings per share reconciliation

A reconciliation of the weighted average common shares outstanding used in the basic and diluted earnings per share calculation was as follows:



	2019	2018	2017
	(In thousands)
Weighted average common shares outstanding - basic	198,612	195,720	195,304
Effect of dilutive performance share awards	14	430	383
Weighted average common shares outstanding - diluted	198,626	196,150	195,687
Shares excluded from the calculation of diluted earnings per share	164	10	—

After-tax changes in the components of accumulated other comprehensive income (loss)

The after-tax changes in the components of accumulated other comprehensive loss at December 31, 2019, 2018 and 2017, were as follows:



	Net Unrealized Loss on Derivative Instruments Qualifying as Hedges			Post- retirement Liability Adjustment			Foreign Currency Translation Adjustment			Net Unrealized Gain (Loss) on Available- for-sale Investments			Total Accumulated Other Comprehensive Loss
	(In thousands)
At December 31, 2017	$	(1,934	)	$	(35,163	)	$	(155	)	$	(82	)	$	(37,334	)
Other comprehensive income (loss) before reclassifications	—			4,441			(61		)	(144		)	4,236
Amounts reclassified from accumulated other comprehensive loss	162			2,173			249			131			2,715
Net current-period other comprehensive income (loss)	162			6,614			188			(13		)	6,951
Reclassification adjustment of prior period tax effects related to TCJA included in accumulated other comprehensive loss	(389		)	(7,520		)	(33		)	(17		)	(7,959		)
At December 31, 2018	(2,161		)	(36,069		)	—			(112		)	(38,342		)
Other comprehensive income (loss) before reclassifications	—			(6,151		)	—			134			(6,017		)
Amounts reclassified from accumulated other comprehensive loss	731			1,486			—			40			2,257
Net current-period other comprehensive income (loss)	731			(4,665		)	—			174			(3,760		)
At December 31, 2019	$	(1,430	)	$	(40,734	)	$	—		$	62		$	(42,102	)

Reclassification out of accumulated other comprehensive income (loss)

The following amounts were reclassified out of accumulated other comprehensive loss into net income. The amounts presented in parenthesis indicate a decrease to net income on the Consolidated Statements of Income. The reclassifications for the years ended December 31 were as follows:



	2019			2018			Location on Consolidated Statements of Income
	(In thousands)
Reclassification adjustment for loss on derivative instruments included in net income	$	(591	)	$	(591	)	Interest expense
	(140		)	429			Income taxes
	(731		)	(162		)
Amortization of postretirement liability losses included in net periodic benefit cost	(1,962		)	(2,894		)	Other income
	476			721			Income taxes
	(1,486		)	(2,173		)
Reclassification adjustment for foreign currency translation adjustment included in net income	—			(324		)	Other income
	—			75			Income taxes
	—			(249		)
Reclassification adjustment for loss on available-for-sale investments included in net income	(50		)	(166		)	Other income
	10			35			Income taxes
	(40		)	(131		)
Total reclassifications	$	(2,257	)	$	(2,715	)