XML 70 R14.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Comprehensive income (loss) | 3 Months Ended
--- | ---
Mar. 31, 2014
Comprehensive income (loss) [Abstract] |
Comprehensive income (loss) | Comprehensive income (loss) The after-tax changes in the components of accumulated other comprehensive loss at March 31, 2014, were as follows:
| Net Unrealized Gain (Loss) on Derivative Instruments Qualifying as Hedges | Postretirement 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, 2013 | $ | (3,765 | ) | $ | (33,807 | ) | $ | (667 | ) | $ | 34 |  | $ | (38,205 | )
Other comprehensive income (loss) before reclassifications | — |  | — |  | 46 |  | (36 | ) | 10 |
Amounts reclassified from accumulated other comprehensive loss | 344 |  | 275 |  | — |  | 38 |  | 657 |
Net current-period other comprehensive income | 344 |  | 275 |  | 46 |  | 2 |  | 667 |
Balance at March 31, 2014 | $ | (3,421 | ) | $ | (33,532 | ) | $ | (621 | ) | $ | 36 |  | $ | (37,538 | )
The after-tax changes in the components of accumulated other comprehensive loss at March 31, 2013, were as follows:
| Net Unrealized Gain (Loss) on Derivative Instruments Qualifying as Hedges | Postretirement 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 | (5,849 | ) | — |  | 88 |  | (44 | ) | (5,805 | )
Amounts reclassified from accumulated other comprehensive loss | (2,772 | ) | 648 |  | — |  | 35 |  | (2,089 | )
Net current-period other comprehensive income (loss) | (8,621 | ) | 648 |  | 88 |  | (9 | ) | (7,894 | )
Balance at March 31, 2013 | $ | (2,603 | ) | $ | (53,699 | ) | $ | (423 | ) | $ | 110 |  | $ | (56,615 | )
Reclassifications out of accumulated other comprehensive loss were as follows:
| Three Months Ended | Location on Consolidated Statements of Income
| March 31, 2014 | March 31, 2013
| (In thousands) |
Reclassification adjustment for gain (loss) on derivative instruments included in net income: |  |  |
Commodity derivative instruments | $ | (388 | ) | $ | 4,513 |  | Operating revenues
Interest rate derivative instruments | (160 | ) | (115 | ) | Interest expense
| (548 | ) | 4,398 |  |
| 204 |  | (1,626 | ) | Income taxes
| (344 | ) | 2,772 |  |
Amortization of postretirement liability losses included in net periodic benefit cost | (443 | ) | (967 | ) | (a)
| 168 |  | 319 |  | Income taxes
| (275 | ) | (648 | ) |
Reclassification adjustment for loss on available-for-sale investments included in net income | (58 | ) | (54 | ) | Other income
| 20 |  | 19 |  | Income taxes
| (38 | ) | (35 | ) |
Total reclassifications | $ | (657 | ) | $ | 2,089 |  |
(a) Included in net periodic benefit cost (credit). For more information, see Note 17.

X
- Details
Name: | mdu_ComprehensiveIncomeLossAbstract
Namespace Prefix: | mdu_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e637-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e681-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e689-108580 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669619-108580 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e640-108580 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e716-108580 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e709-108580 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Reclassification Adjustments -URI http://asc.fasb.org/extlink&oid=6522872 + Details
Name: | us-gaap_ComprehensiveIncomeNoteTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration