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Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016
Net income (loss) | $ 87,351 | $ 82,986 | $ 165,891 | $ (132,988)
Net unrealized gain on derivative instruments qualifying as hedges: |  |  |  |
Reclassification adjustment for loss on derivative instruments included in net income (loss), net of tax of $56 and $56 for the three months ended and $168 and $170 for the nine months ended in 2017 and 2016, respectively | 92 | 92 | 275 | 275
Postretirement liability adjustment: |  |  |  |
Amortization of postretirement liability (gains) losses included in net periodic benefit cost (credit), net of tax of $203 and $143 for the three months ended and $609 and $(676) for the nine months ended in 2017 and 2016, respectively | 333 | 236 | 1,002 | (1,111)
Reclassification of postretirement liability adjustment from regulatory asset, net of tax of $0 and $0 for the three months ended and $(725) and $0 for the nine months ended in 2017 and 2016, respectively | 0 | 0 | (917) | 0
Postretirement liability adjustment | 333 | 236 | 85 | (1,111)
Foreign currency translation adjustment: |  |  |  |
Foreign currency translation adjustment recognized during the period, net of tax of $9 and $(2) for the three months ended and $5 and $32 for the nine months ended in 2017 and 2016, respectively | 15 | (4) | 9 | 52
Net unrealized gain (loss) on available-for-sale investments: |  |  |  |
Net unrealized loss on available-for-sale investments arising during the period, net of tax of $(10) and $(23) for the three months ended and $(38) and $(35) for the nine months ended in 2017 and 2016, respectively | (19) | (42) | (70) | (65)
Reclassification adjustment for loss on available-for-sale investments included in net income (loss), net of tax of $14 and $18 for the three months ended and $50 and $57 for the nine months ended in 2017 and 2016, respectively | 27 | 33 | 93 | 106
Net unrealized gain (loss) on available-for-sale investments | 8 | (9) | 23 | 41
Other comprehensive income (loss) | 448 | 315 | 392 | (743)
Comprehensive income (loss) | 87,799 | 83,301 | 166,283 | (133,731)
Loss from discontinued operations attributable to noncontrolling interest | 0 | 0 | 0 | (131,691)
Comprehensive income (loss) attributable to common stockholders | $ 87,799 | $ 83,301 | $ 166,283 | $ (2,040)

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