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Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013
Consolidated Statements of Comprehensive Income [Abstract] |  |  |  |
Net income | $ 102,121 | $ 84,432 | $ 211,588 | $ 187,280
Net unrealized gain (loss) on derivative instruments qualifying as hedges: |  |  |  |
Net unrealized loss on derivative instruments arising during the period, net of tax of $0 and $0 for the three months ended and $0 and $(3,116) for the nine months ended in 2014 and 2013, respectively | 0 | 0 | 0 | (5,594)
Reclassification adjustment for (gain) loss on derivative instruments included in net income, net of tax of $50 and $(297) for the three months ended and $264 and $(2,246) for the nine months ended in 2014 and 2013, respectively | 82 | (510) | 439 | (3,678)
Net unrealized gain (loss) on derivative instruments qualifying as hedges | 82 | (510) | 439 | (9,272)
Amortization of postretirement liability losses included in net periodic benefit cost, net of tax of $159 and $166 for the three months ended and $477 and $1,027 for the nine months ended in 2014 and 2013, respectively | 261 | 271 | 781 | 1,344
Foreign currency translation adjustment recognized during the period, net of tax of $(89) and $(12) for the three months ended and $(36) and $(209) for the nine months ended in 2014 and 2013, respectively | (146) | (20) | (58) | (351)
Reclassification adjustment for loss on foreign currency translation adjustment included in net income, net of tax of $0 and $70 for the three months ended and $0 and $70 for the nine months ended in 2014 and 2013, respectively | 0 | 115 | 0 | 143
Foreign currency translation adjustment | (146) | 95 | (58) | (208)
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 $(33)and $(5) for the three months ended and $(48) and $(106) for the nine months ended in 2014 and 2013, respectively | (62) | (10) | (89) | (197)
Reclassification adjustment for loss on available-for-sale investments included in net income, net of tax of $16 and $20 for the three months ended and $54 and $63 for the nine months ended in 2014 and 2013, respectively | 31 | 38 | 100 | 117
Net unrealized gain (loss) on available-for-sale investments | (31) | 28 | 11 | (80)
Other comprehensive income (loss) | 166 | (116) | 1,173 | (8,216)
Comprehensive income | 102,287 | 84,316 | 212,761 | 179,064
Comprehensive loss attributable to noncontrolling interest | (1,088) | (24) | (2,390) | (204)
Comprehensive income attributable to common stockholders | $ 103,375 | $ 84,340 | $ 215,151 | $ 179,268

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