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Nuclear Decommissioning Trusts (Details) - USD ($) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2016 | Mar. 31, 2015 | Dec. 31, 2015
Nuclear decommissioning trust fund assets |  |  |
Fair Value | $ 751,954 |  | $ 735,196
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds |  |  |
Proceeds from the sale of securities | 141,809 | $ 115,282 |
Fair value of fixed income securities, summarized by contractual maturities |  |  |
Total | 751,954 |  | 735,196
Arizona Public Service Company |  |  |
Nuclear decommissioning trust fund assets |  |  |
Fair Value | 751,954 |  | 735,196
Unrealized Gains | 178,040 |  | 169,053
Unrealized Losses | (741) |  | (2,760)
Net payables for securities purchases | (1,898) |  | (335)
Realized gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds |  |  |
Realized gains | 2,438 | 1,195 |
Realized losses | (1,786) | (525) |
Proceeds from the sale of securities | 141,809 | $ 115,282 |
Fair value of fixed income securities, summarized by contractual maturities |  |  |
Total | 751,954 |  | 735,196
Arizona Public Service Company | Equity Securities |  |  |
Nuclear decommissioning trust fund assets |  |  |
Fair Value | 319,971 |  | 314,957
Unrealized Gains | 159,790 |  | 157,098
Unrealized Losses | (65) |  | (115)
Fair value of fixed income securities, summarized by contractual maturities |  |  |
Total | 319,971 |  | 314,957
Arizona Public Service Company | Fixed income securities. |  |  |
Nuclear decommissioning trust fund assets |  |  |
Fair Value | 433,881 |  | 420,574
Unrealized Gains | 18,250 |  | 11,955
Unrealized Losses | (676) |  | (2,645)
Fair value of fixed income securities, summarized by contractual maturities |  |  |
Less than one year | 11,633 |  |
1 year - 5 years | 126,221 |  |
5 years - 10 years | 101,773 |  |
Greater than 10 years | 194,254 |  |
Total | $ 433,881 |  | $ 420,574

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- Definition The fair value of investments held in a trust fund to pay for the costs of decontaminating and decommissioning facilities, whether such amount is presented as a separate caption or as a parenthetical disclosure on the balance sheet. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
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