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Comprehensive income (loss) (Tables) | 9 Months Ended
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Sep. 30, 2013
Comprehensive income (loss) [Abstract] |
Comprehensive income (loss) | The after-tax changes in the components of accumulated other comprehensive loss as of September 30, 2013, were as follows:
| Net Unrealized Gain (Loss) on Derivative Instruments Qualifying as Hedges | Net Unrealized Gain (Loss) on Available-for-sale Investments | Postretirement Liability Adjustment | Foreign Currency Translation Adjustment | Total Accumulated Other Comprehensive Loss
| (In thousands)
Balance at December 31, 2012 | $ | 6,018 |  | $ | 119 |  | $ | (54,347 | ) | $ | (511 | ) | $ | (48,721 | )
Other comprehensive income (loss) before reclassifications | (5,594 | ) | (197 | ) | — |  | (351 | ) | (6,142 | )
Amounts reclassified from accumulated other comprehensive loss | (3,678 | ) | 117 |  | 1,344 |  | 143 |  | (2,074 | )
Net current-period other comprehensive income (loss) | (9,272 | ) | (80 | ) | 1,344 |  | (208 | ) | (8,216 | )
Balance at September 30, 2013 | $ | (3,254 | ) | $ | 39 |  | $ | (53,003 | ) | $ | (719 | ) | $ | (56,937 | )
Reclassification out of accumulated other comprehensive income | Reclassifications out of accumulated other comprehensive loss were as follows:
| Three Months Ended | Nine Months Ended | Location on Consolidated Statements of Income
| September 30, 2013 | September 30, 2013
| (In thousands) |
Reclassification adjustment for gain (loss) on derivative instruments included in net income |  |  |
Commodity derivative instruments | $ | 1,007 |  | $ | 6,903 |  | Operating revenues
Interest rate derivative instruments | (200 | ) | (979 | ) | Interest expense
| 807 |  | 5,924 |  |
| (297 | ) | (2,246 | ) | Income taxes
| 510 |  | 3,678 |  |
Amortization of postretirement liability losses included in net periodic benefit cost | (437 | ) | (2,371 | ) | (a)
| 166 |  | 1,027 |  | Income taxes
| (271 | ) | (1,344 | ) |
Reclassification adjustment for loss on available-for-sale investments included in net income | (58 | ) | (180 | ) | Other income
| 20 |  | 63 |  | Income taxes
| (38 | ) | (117 | ) |
Reclassification adjustment for loss on foreign currency translation adjustment included in net income | (185 | ) | (213 | ) | Earnings (loss) from equity method investments
| 70 |  | 70 |  | Earnings (loss) from equity method investments
| (115 | ) | (143 | ) |
Total reclassifications | $ | 86 |  | $ | 2,074 |  |
(a) Included in net periodic benefit cost (credit). For more information, see Note 18.

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- Definition Tabular disclosure of information about items reclassified out of accumulated other comprehensive income (loss). + References No definition available. + Details
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- Definition Tabular disclosure of the components of accumulated other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669686-108580 + Details
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