Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2018

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



	2018		2017
	(In thousands)
Short-term retainage*	$	56,228	$	57,134
Long-term retainage**	4,152		1,410
Total retainage	$	60,380	$	58,544


*	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:



	2018		2017
	(In thousands)
Aggregates held for resale	$	139,681	$	115,268
Asphalt oil	54,741		30,360
Materials and supplies	23,611		18,650
Merchandise for resale	22,552		14,905
Natural gas in storage (current)	22,117		20,950
Other	24,607		26,450
Total	$	287,309	$	226,583

AFUDC and interest capitailized

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



	2018		2017		2016
	(In thousands)
AFUDC - borrowed	$	2,290	$	966	$	914
AFUDC - equity	$	1,897	$	909	$	565

Property, plant and equipment

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



	2018		2017		Weighted Average Depreciable Life in Years
	(Dollars in thousands, where applicable)
Regulated:
Electric:
Generation	$	1,131,484	$	1,034,765	49
Distribution	430,750		415,543		46
Transmission	302,315		296,941		64
Construction in progress	161,893		117,906		—
Other	122,127		117,109		13
Natural gas distribution:
Distribution	1,981,356		1,831,795		47
Construction in progress	21,028		19,823		—
Other	496,708		468,227		16
Pipeline and midstream:
Transmission	585,594		516,932		54
Gathering	37,829		37,837		20
Storage	49,101		45,629		61
Construction in progress	5,915		17,488		—
Other	45,763		41,054		33
Nonregulated:
Pipeline and midstream:
Gathering and processing	31,094		31,678		19
Construction in progress	86		17		—
Other	9,577		9,649		10
Construction materials and contracting:
Land	109,541		95,745		—
Buildings and improvements	114,905		102,435		20
Machinery, vehicles and equipment	1,090,790		947,979		12
Construction in progress	22,507		7,750		—
Aggregate reserves	430,263		406,139		*
Construction services:
Land	5,216		5,216		—
Buildings and improvements	29,795		27,351		25
Machinery, vehicles and equipment	145,859		137,924		6
Other	7,716		6,774		3
Other:
Land	2,648		2,837		—
Other	25,461		28,286		14
Less accumulated depreciation, depletion and amortization	2,818,644		2,691,641
Net property, plant and equipment	$	4,578,677	$	4,079,188


*	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:



	2018	2017	2016
	(In thousands)
Weighted average common shares outstanding - basic	195,720	195,304	195,299
Effect of dilutive performance share awards	430	383	319
Weighted average common shares outstanding - diluted	196,150	195,687	195,618
Shares excluded from the calculation of diluted earnings per share	10	—	—

Schedule of New Accounting Pronouncements and Changes in Accounting Principles

The cumulative effect of the changes made to the Consolidated Balance Sheet were as follows:



	December 31, 2017		Adjustments			January 1, 2018
	(In thousands)
Liabilities and Stockholders' Equity
Current liabilities:
Other accrued liabilities	$	186,010	$	903		$	186,913
Deferred credits and other liabilities:
Deferred income taxes	347,271		(332		)	346,939
Other	1,179,140		399			1,179,539
Commitments and contingencies
Stockholders' equity:
Common stockholders' equity:
Retained earnings	1,040,748		(970		)	1,039,778

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

The after-tax changes in the components of accumulated other comprehensive loss as of December 31, 2018, 2017 and 2016, were as follows:



	Net Unrealized Gain (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)
Balance at December 31, 2016	$	(2,300	)	$	(33,221	)	$	(149	)	$	(63	)	$	(35,733	)
Other comprehensive loss before reclassifications	—			(1,812		)	(6		)	(139		)	(1,957		)
Amounts reclassified from accumulated other comprehensive loss	366			1,013			—			120			1,499
Amounts reclassified to accumulated other comprehensive loss from a regulatory asset	—			(1,143		)	—			—			(1,143		)
Net current-period other comprehensive income (loss)	366			(1,942		)	(6		)	(19		)	(1,601		)
Balance 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		)
Balance at December 31, 2018	$	(2,161	)	$	(36,069	)	$	—		$	(112	)	$	(38,342	)

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:



	2018			2017			Location on Consolidated Statements of Income
	(In thousands)
Reclassification adjustment for loss on derivative instruments included in net income	$	(591	)	$	(590	)	Interest expense
	429			224			Income taxes
	(162		)	(366		)
Amortization of postretirement liability losses included in net periodic benefit cost (credit)	(2,894		)	(1,658		)	Other income
	721			645			Income taxes
	(2,173		)	(1,013		)
Reclassification adjustment for loss on 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	(166		)	(185		)	Other income
	35			65			Income taxes
	(131		)	(120		)
Total reclassifications	$	(2,715	)	$	(1,499	)