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Summary of significant accounting policies (Tables) | 12 Months Ended
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Dec. 31, 2014
Accounting Policies [Abstract] |
Inventories | Inventories at December 31 consisted of:
| 2014 |  | 2013 |
| (In thousands)
Aggregates held for resale | $ | 108,161 |  | $ | 101,568 |
Materials and supplies | 65,683 |  | 69,808 |
Asphalt oil | 42,135 |  | 38,099 |
Merchandise for resale | 24,420 |  | 21,720 |
Natural gas in storage (current) | 19,302 |  | 16,417 |
Other | 41,110 |  | 34,779 |
Total | $ | 300,811 |  | $ | 282,391 |
AFUDC and interest capitailized | The amount of AFUDC and interest capitalized for the years ended December 31 were as follows:
| 2014 |  | 2013 |  | 2012 |
|  | (In thousands) |  |
Interest capitalized | $ | 8,586 |  | $ | 6,033 |  | $ | 8,659 |
AFUDC - borrowed | $ | 3,022 |  | $ | 2,767 |  | $ | 2,483 |
AFUDC - equity | $ | 5,803 |  | $ | 3,322 |  | $ | 4,530 |
Property, plant and equipment | Property, plant and equipment at December 31 was as follows:
| 2014 |  | 2013 |  | Weighted Average Depreciable Life in Years
| (Dollars in thousands, where applicable)
Regulated: |  |  |
Electric: |  |  |
Generation | $ | 627,952 |  | $ | 570,394 |  | 42
Distribution | 343,692 |  | 308,202 |  | 39
Transmission | 229,997 |  | 196,824 |  | 48
Construction in progress | 150,445 |  | 141,365 |  | -
Other | 105,015 |  | 99,037 |  | 15
Natural gas distribution: |  |  |  |  |
Distribution | 1,481,390 |  | 1,384,587 |  | 40
Construction in progress | 59,310 |  | 46,763 |  | -
Other | 364,059 |  | 345,551 |  | 27
Pipeline and energy services: |  |  |  |  |
Transmission | 449,276 |  | 418,594 |  | 53
Gathering | 39,595 |  | 39,597 |  | 20
Storage | 43,994 |  | 42,939 |  | 60
Construction in progress | 5,386 |  | 6,937 |  | -
Other | 39,910 |  | 39,504 |  | 33
Nonregulated: |  |  |  |  |
Pipeline and energy services: |  |  |  |  |
Midstream | 227,598 |  | 213,063 |  | 16
Construction in progress | 314,304 |  | 188,641 |  | -
Other | 100,170 |  | 12,897 |  | 18
Exploration and production: |  |  |  |  |
Oil and natural gas properties | 3,337,177 |  | 3,017,879 |  | *
Other | 65,702 |  | 42,969 |  | 8
Construction materials and contracting: |  |  |  |  |
Land | 125,372 |  | 125,551 |  | -
Buildings and improvements | 70,566 |  | 70,000 |  | 19
Machinery, vehicles and equipment | 921,564 |  | 906,774 |  | 12
Construction in progress | 8,709 |  | 13,315 |  | -
Aggregate reserves | 403,731 |  | 394,715 |  | **
Construction services: |  |  |  |  |
Land | 5,265 |  | 4,821 |  | -
Buildings and improvements | 17,936 |  | 16,628 |  | 20
Machinery, vehicles and equipment | 112,973 |  | 105,991 |  | 6
Other | 8,221 |  | 7,508 |  | 4
Other: |  |  |  |  |
Land | 2,837 |  | 2,837 |  | -
Other | 48,100 |  | 47,160 |  | 23
Eliminations | (17,075 | ) | (7,177 | ) |
Less accumulated depreciation, depletion and amortization | 4,166,407 |  | 3,872,487 |  |
Net property, plant and equipment | $ | 5,526,764 |  | $ | 4,931,379 |  |
* | Amortized on the units-of-production method based on total proved reserves at a BOE average rate of $21.17, $17.41 and $15.28 for the years ended December 31, 2014, 2013 and 2012, respectively. Includes oil and natural gas properties accounted for under the full-cost method, of which $132.1 million and $124.9 million were excluded from amortization at December 31, 2014 and 2013, respectively.
** | Depleted on the units-of-production method.
SEC Defined Pricing | SEC Defined Prices for each quarter in 2014 were as follows:
SEC Defined Prices for the 12 months ended | NYMEX Oil Price (per Bbl) |  | Henry Hub Gas Price (per MMBtu) |  | Ventura Gas Price (per MMBtu) |
December 31, 2014 | $ | 94.99 |  | $ | 4.34 |  | $ | 7.71 |
September 30, 2014 | 99.08 |  | 4.24 |  | 7.60 |
June 30, 2014 | 100.27 |  | 4.10 |  | 7.47 |
March 31, 2014 | 98.46 |  | 3.99 |  | 7.33 |
For purposes of comparison, first-of-the-month prices were as follows:
| NYMEX Oil Price (per Bbl) |  | Henry Hub Gas Price (per MMBtu) |  | Ventura Gas Price (per MMBtu) |
January 2015 | $ | 53.27 |  | $ | 3.00 |  | $ | 3.06 |
February 2015 | 48.24 |  | 2.68 |  | 2.78 |
Summary of natural gas and oil properties not subject to amortization | The following table summarizes the Company's oil and natural gas properties not subject to amortization at December 31, 2014, in total and by the year in which such costs were incurred:
|  | Year Costs Incurred
| Total |  | 2014 |  | 2013 |  | 2012 |  | 2011 and prior |
| (In thousands)
Acquisition | $ | 97,795 |  | $ | 82,233 |  | $ | 1,528 |  | $ | 475 |  | $ | 13,559 |
Development | 14,312 |  | 3,361 |  | 9,928 |  | 484 |  | 539 |
Exploration | 18,221 |  | 10,961 |  | 3,126 |  | 3,885 |  | 249 |
Capitalized interest | 1,813 |  | 1,343 |  | 203 |  | 67 |  | 200 |
Total costs not subject to amortization | $ | 132,141 |  | $ | 97,898 |  | $ | 14,785 |  | $ | 4,911 |  | $ | 14,547 |
Percentage-of-completion method | Costs and estimated earnings in excess of billings and billings in excess of costs and estimated earnings on uncompleted contracts at December 31, were as follows:
| 2014 |  | 2013 |
| (In thousands)
Costs and estimated earnings in excess of billings on uncompleted contracts | $ | 58,243 |  | $ | 60,828 |
Billings in excess of costs and estimated earnings on uncompleted contracts | $ | 47,011 |  | $ | 84,189 |
Amounts representing balances billed but not paid by customers under retainage provisions in contracts at December 31, were as follows:
| 2014 |  | 2013 |
| (In thousands)
Short-term retainage* | $ | 47,551 |  | $ | 55,906 |
Long-term retainage** | 1,053 |  | 4,229 |
Total retainage | $ | 48,604 |  | $ | 60,135 |
* | Expected to be paid within one year or less and included in receivables, net.
** | Included in deferred charges and other assets - other.
Schedule of earnings per share reconciliation | Net income (loss) was the same for both the basic and diluted earnings (loss) per share calculations. A reconciliation of the weighted average common shares outstanding used in the basic and diluted earnings (loss) per share calculation was as follows:
| 2014 |  | 2013 |  | 2012 |
|  | (In thousands) |  |
Weighted average common shares outstanding - basic | 192,507 |  | 188,855 |  | 188,826 |
Effect of dilutive performance share awards | 80 |  | 838 |  | — |
Weighted average common shares outstanding - diluted | 192,587 |  | 189,693 |  | 188,826 |
Shares excluded from the calculation of diluted earnings per share | — |  | — |  | 58 |
Cash expenditures for interest and income taxes and noncash investing transactions | Cash expenditures for interest and income taxes for the years ended December 31 were as follows:
| 2014 |  | 2013 |  | 2012 |
|  | (In thousands) |  |
Interest, net of amount capitalized | $ | 81,351 |  | $ | 81,689 |  | $ | 74,378 |
Income taxes paid, net | $ | 69,087 |  | $ | 24,857 |  | $ | 3,277 |
Noncash investing transactions at December 31 were as follows:
| 2014 |  | 2013 |  | 2012 |
|  | (In thousands) |  |
Property, plant and equipment additions in accounts payable | $ | 103,327 |  | $ | 67,129 |  | $ | 76,205 |
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, 2014, 2013 and 2012, 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, 2012 | $ | 6,018 |  | $ | (54,347 | ) | $ | (511 | ) | $ | 119 |  | $ | (48,721 | )
Other comprehensive income (loss) before reclassifications | (5,594 | ) | 18,539 |  | (299 | ) | (194 | ) | 12,452 |
Amounts reclassified from accumulated other comprehensive loss | (4,189 | ) | 2,001 |  | 143 |  | 109 |  | (1,936 | )
Net current-period other comprehensive income (loss) | (9,783 | ) | 20,540 |  | (156 | ) | (85 | ) | 10,516 |
Balance at December 31, 2013 | (3,765 | ) | (33,807 | ) | (667 | ) | 34 |  | (38,205 | )
Other comprehensive income (loss) before reclassifications | — |  | (12,409 | ) | (162 | ) | (154 | ) | (12,725 | )
Amounts reclassified from accumulated other comprehensive loss | 694 |  | 796 |  | — |  | 135 |  | 1,625 |
Amounts reclassified from accumulated other comprehensive loss to a regulatory asset | — |  | 7,202 |  | — |  | — |  | 7,202 |
Net current-period other comprehensive income (loss) | 694 |  | (4,411 | ) | (162 | ) | (19 | ) | (3,898 | )
Balance at December 31, 2014 | $ | (3,071 | ) | $ | (38,218 | ) | $ | (829 | ) | $ | 15 |  | $ | (42,103 | )
Reclassification out of accumulated other comprehensive income (loss) | Reclassifications out of accumulated other comprehensive loss for the year ended December 31 were as follows:
| 2014 |  | 2013 |  | Location on Consolidated Statements of Income
| (In thousands) |
Reclassification adjustment for gain (loss) on derivative instruments included in net income: |  |  |
Commodity derivative instruments | $ | (468 | ) | $ | 7,803 |  | Operating revenues
Interest rate derivative instruments | (639 | ) | (1,066 | ) | Interest expense
| (1,107 | ) | 6,737 |  |
| 413 |  | (2,548 | ) | Income taxes
| (694 | ) | 4,189 |  |
Amortization of postretirement liability losses included in net periodic benefit cost | (1,288 | ) | (3,277 | ) | (a)
| 492 |  | 1,276 |  | Income taxes
| (796 | ) | (2,001 | ) |
Reclassification adjustment for loss on foreign currency translation adjustment included in net income | — |  | (213 | ) | Earnings (loss) from equity method investments
| — |  | 70 |  | Earnings (loss) from equity method investments
| — |  | (143 | ) |
Reclassification adjustment for loss on available-for-sale investments included in net income | (208 | ) | (168 | ) | Other income
| 73 |  | 59 |  | Income taxes
| (135 | ) | (109 | ) |
Total reclassifications | $ | (1,625 | ) | $ | 1,936 |  |
(a) | Included in net periodic benefit cost (credit). For more information, see Note 16.

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