XML 36 R19.htm IDEA: XBRL DOCUMENT
v3.4.0.3

Nuclear Decommissioning Trusts | 3 Months Ended
--- | ---
Mar. 31, 2016
Investments, Debt and Equity Securities [Abstract] |
Nuclear Decommissioning Trusts | Nuclear Decommissioning Trusts To fund the costs APS expects to incur to decommission Palo Verde, APS established external decommissioning trusts in accordance with NRC regulations. Third-party investment managers are authorized to buy and sell securities per stated investment guidelines. The trust funds are invested in fixed income securities and equity securities. APS classifies investments in decommissioning trust funds as available for sale. As a result, we record the decommissioning trust funds at their fair value on our Condensed Consolidated Balance Sheets. See Note 10 for a discussion of how fair value is determined and the classification of the nuclear decommissioning trust investments within the fair value hierarchy. Because of the ability of APS to recover decommissioning costs in rates and in accordance with the regulatory treatment for decommissioning trust funds, we have deferred realized and unrealized gains and losses (including other-than-temporary impairments on investment securities) in other regulatory liabilities. The following table includes the unrealized gains and losses based on the original cost of the investment and summarizes the fair value of APS’s nuclear decommissioning trust fund assets at March 31, 2016 and December 31, 2015 (dollars in thousands):
| Fair Value |  | Total Unrealized Gains |  | Total Unrealized Losses
March 31, 2016 |  |  |  |  |  |  |  |
Equity securities | $ | 319,971 |  |  | $ | 159,790 |  |  | $ | (65 | )
Fixed income securities | 433,881 |  |  | 18,250 |  |  | (676 | )
Net payables (a) | (1,898 | ) |  | — |  |  | — |
Total | $ | 751,954 |  |  | $ | 178,040 |  |  | $ | (741 | )
| Fair Value |  | Total Unrealized Gains |  | Total Unrealized Losses
December 31, 2015 |  |  |  |  |  |  |  |
Equity securities | $ | 314,957 |  |  | $ | 157,098 |  |  | $ | (115 | )
Fixed income securities | 420,574 |  |  | 11,955 |  |  | (2,645 | )
Net payables (a) | (335 | ) |  | — |  |  | — |
Total | $ | 735,196 |  |  | $ | 169,053 |  |  | $ | (2,760 | )
(a) | Net payables relate to pending purchases and sales of securities.
The costs of securities sold are determined on the basis of specific identification. The following table sets forth approximate gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds (dollars in thousands):
| Three Months Ended March 31,
| 2016 |  | 2015
Realized gains | $ | 2,438 |  |  | $ | 1,195 |
Realized losses | (1,786 | ) |  | (525 | )
Proceeds from the sale of securities (a) | 141,809 |  |  | 115,282 |
(a) | Proceeds are reinvested in the trust.
The fair value of fixed income securities, summarized by contractual maturities, at March 31, 2016 is as follows (dollars in thousands):
| Fair Value
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 |

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for investments in certain debt and equity securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -Glossary Debt Security -URI http://asc.fasb.org/extlink&oid=6509901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27232-111563 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -Glossary Equity Security -URI http://asc.fasb.org/extlink&oid=6511694 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27357-111563 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27405-111563 + Details
Name: | us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration