v2.4.0.6

Accounting for derivative instruments and hedging activities (Tables) | 12 Months Ended
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Dec. 31, 2012
Accounting for derivative instruments and hedging activities |
Schedule of notional volumes of forecasted transactions |
|  | Units |  | December 31, 2012 |  | December 31, 2011 |
--- | --- | --- | --- | --- | --- | --- | ---
Natural gas swaps |  | Natural Gas (Mmbtu) |  |  | 10,640 |  |  | 14,140 |
Gas Purchase Agreements |  | Natural Gas (GJ) |  |  | 49,810 |  |  | — |
Interest Rate Swaps |  | Interest (US$) |  |  | 140,154 |  |  | 52,711 |
Currency forwards |  | Cdn$ |  |  | 176,550 |  |  | 312,533 |
Schedule of fair value of derivative instruments |
|  | December 31, 2012 |
--- | --- | --- | ---
|  | Derivative Assets |  | Derivative Liabilities |
Derivative instruments designated as cash flow hedges: |  |  |  |  |  |  |
Interest rate swaps current |  | $ | — |  | $ | 1,340 |
Interest rate swaps long-term |  |  | — |  |  | 5,167 |
Total derivative instruments designated as cash flow hedges |  |  | — |  |  | 6,507 |
Derivative instruments not designated as cash flow hedges: |  |  |  |  |  |  |
Interest rate swaps current |  |  | — |  |  | 7,261 |
Interest rate swaps long-term |  |  | 69 |  |  | 27,713 |
Foreign currency forward contracts current |  |  | 9,456 |  |  | — |
Foreign currency forward contracts long-term |  |  | 10,998 |  |  | — |
Natural gas swaps current |  |  | — |  |  | — |
Natural gas swaps long-term |  |  | 117 |  |  | 3,864 |
Gas purchase agreements current |  |  | 71 |  |  | 24,544 |
Gas purchase agreements long-term |  |  | — |  |  | 81,359 |
Total derivative instruments not designated as cash flow hedges |  |  | 20,711 |  |  | 144,741 |
Total derivative instruments |  | $ | 20,711 |  | $ | 151,248 |
|  | December 31, 2011 |
|  | Derivative Assets |  | Derivative Liabilities |
Derivative instruments designated as cash flow hedges: |  |  |  |  |  |  |
Interest rate swaps current |  | $ | — |  | $ | 1,561 |
Interest rate swaps long-term |  |  | — |  |  | 5,317 |
Total derivative instruments designated as cash flow hedges |  |  | — |  |  | 6,878 |
Derivative instruments not designated as cash flow hedges: |  |  |  |  |  |  |
Interest rate swaps current |  |  | — |  |  | 2,587 |
Interest rate swaps long-term |  |  | — |  |  | 9,637 |
Foreign currency forward contracts current |  |  | 10,630 |  |  | 224 |
Foreign currency forward contracts long-term |  |  | 22,224 |  |  | 221 |
Natural gas swaps current |  |  | — |  |  | 16,439 |
Natural gas swaps long-term |  |  | — |  |  | 18,216 |
Gas purchase agreements current |  |  | — |  |  | — |
Gas purchase agreements long-term |  |  | — |  |  | — |
Total derivative instruments not designated as cash flow hedges |  |  | 32,854 |  |  | 47,324 |
Total derivative instruments |  | $ | 32,854 |  | $ | 54,202 |
Schedule of changes in OCI attributable to derivative financial instruments |
For the year ended December 31, 2012 |  | Interest Rate Swaps |  | Natural Gas Swaps |  | Total |
--- | --- | --- | --- | --- | --- | --- | ---
Accumulated OCI balance at January 1, 2012 |  | $ | (1,704 | ) | $ | 321 |  | $ | (1,383 | )
Change in fair value of cash flow hedges |  |  | (949 | ) |  | — |  |  | (949 | )
Realized from OCI during the period |  |  | 1,120 |  |  | (232 | ) |  | 888 |
Accumulated OCI balance at December 31, 2012 |  | $ | (1,533 | ) | $ | 89 |  | $ | (1,444 | )
Gains (losses) expected to be realized from OCI in the next 12 months, net of $593 tax |  | $ | 979 |  | $ | (89 | ) | $ | 890 |
For the year ended December 31, 2011 |  | Interest Rate Swaps |  | Natural Gas Swaps |  | Total |
Accumulated OCI balance at January 1, 2011 |  | $ | (427 | ) | $ | 682 |  | $ | 255 |
Change in fair value of cash flow hedges |  |  | (2,647 | ) |  | — |  |  | (2,647 | )
Realized from OCI during the period |  |  | 1,370 |  |  | (361 | ) |  | 1,009 |
Accumulated OCI balance at December 31, 2011 |  | $ | (1,704 | ) | $ | 321 |  | $ | (1,383 | )
For the year ended December 31, 2010 |  | Interest Rate Swaps |  | Natural Gas Swaps |  | Total |
Accumulated OCI balance at January 1, 2010 |  | $ | (538 | ) | $ | (321 | ) | $ | (859 | )
Change in fair value of cash flow hedges |  |  | (360 | ) |  | — |  |  | (360 | )
Realized from OCI during the period |  |  | 471 |  |  | 1,003 |  |  | 1,474 |
Accumulated OCI balance at December 31, 2010 |  | $ | (427 | ) | $ | 682 |  | $ | 255 |
Realized (gains) and losses |
Gains and losses for derivative instruments |
Schedule of (gains) and losses for derivative instruments not designated as cash flow hedges |
|  |  |  | Year ended December 31, |
--- | --- | --- | --- | --- | ---
|  | Classification of (gain) loss recognized in income |
|  | 2012 |  | 2011 |  | 2010 |
Gas purchase agreements |  | Fuel |  |  | 43,470 |  |  | — |  |  | — |
Interest rate swaps |  | Interest, net |  |  | 4,584 |  |  | 4,166 |  |  | 1,664 |
Foreign currency forwards |  | Foreign exchange (gain) loss |  |  | (18,483 | ) |  | 5,201 |  |  | (6,625 | )
Unrealized gains and losses |
Gains and losses for derivative instruments |
Schedule of (gains) and losses for derivative instruments not designated as cash flow hedges |
|  |  |  | Year ended December 31, |
--- | --- | --- | --- | --- | ---
|  | Classification of (gain) loss recognized in income |
|  | 2012 |  | 2011 |  | 2010 |
Natural gas swaps |  | Change in fair value of derivatives |  | $ | (1,241 | ) | $ | (2,357 | ) | $ | (148 | )
Gas purchase agreements |  | Change in fair value of derivatives |  | $ | (56,954 | ) |  | — |  |  | — |
Interest rate swaps |  | Change in fair value of derivatives |  |  | (1,077 | ) |  | (12,237 | ) |  | 3,423 |
|  |  |  | $ | (59,272 | ) | $ | (14,594 | ) | $ | 3,275 |
Foreign currency forwards |  | Foreign exchange (gain) loss |  | $ | 11,956 |  | $ | 14,211 |  | $ | (3,542 | )

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- Definition Tabular disclosure of the effective portion of the gains and losses on derivative instruments designated (and non-derivative instruments) designated and qualifying in cash flow hedges and net investment hedges that was recognized in other comprehensive income (loss) during the current period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959 + Details
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- Definition Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition Tabular disclosure of the notional amounts of outstanding derivative positions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959 + Details
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- Definition Tabular disclosure for other derivative instruments not designated as hedging instruments of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959 + Details
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