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Regulatory Matters - Schedule of Regulatory Assets (Details) - USD ($) $ in Thousands | Mar. 31, 2016 | Dec. 31, 2015
--- | --- | ---
Detail of regulatory assets |  |
Regulatory assets, current | $ 168,753 | $ 149,555
Regulatory assets, non-current | 1,203,474 | 1,214,146
Pension |  |
Detail of regulatory assets |  |
Regulatory assets, current | 0 | 0
Regulatory assets, non-current | 610,569 | 619,223
Retired power plant costs |  |
Detail of regulatory assets |  |
Regulatory assets, current | 9,913 | 9,913
Regulatory assets, non-current | 125,037 | 127,518
Income taxes — allowance for funds used during construction (AFUDC) equity |  |
Detail of regulatory assets |  |
Regulatory assets, current | 5,419 | 5,495
Regulatory assets, non-current | 132,149 | 133,712
Deferred fuel and purchased power — mark-to-market (Note 6) |  |
Detail of regulatory assets |  |
Regulatory assets, current | 86,160 | 71,852
Regulatory assets, non-current | 69,708 | 69,697
Four Corners cost deferral (b) |  |
Detail of regulatory assets |  |
Regulatory assets, current | 6,689 | 6,689
Regulatory assets, non-current | 61,910 | 63,582
Income taxes — investment tax credit basis adjustment |  |
Detail of regulatory assets |  |
Regulatory assets, current | 1,852 | 1,766
Regulatory assets, non-current | 48,347 | 48,462
Lost fixed cost recovery (b) |  |
Detail of regulatory assets |  |
Regulatory assets, current | 48,702 | 45,507
Regulatory assets, non-current | 0 | 0
Palo Verde VIEs (Note 5) |  |
Detail of regulatory assets |  |
Regulatory assets, current | 0 | 0
Regulatory assets, non-current | 18,311 | 18,143
Deferred compensation |  |
Detail of regulatory assets |  |
Regulatory assets, current | 0 | 0
Regulatory assets, non-current | 35,871 | 34,751
Deferred property taxes |  |
Detail of regulatory assets |  |
Regulatory assets, current | 0 | 0
Regulatory assets, non-current | 56,589 | 50,453
Loss on reacquired debt |  |
Detail of regulatory assets |  |
Regulatory assets, current | 1,515 | 1,515
Regulatory assets, non-current | 15,996 | 16,375
Tax expense of Medicare subsidy |  |
Detail of regulatory assets |  |
Regulatory assets, current | 1,512 | 1,520
Regulatory assets, non-current | 12,073 | 12,163
Transmission vegetation management |  |
Detail of regulatory assets |  |
Regulatory assets, current | 2,272 | 4,543
Regulatory assets, non-current | 0 | 0
Mead-Phoenix transmission line CIAC |  |
Detail of regulatory assets |  |
Regulatory assets, current | 332 | 332
Regulatory assets, non-current | 10,957 | 11,040
Transmission cost adjustor (b) |  |
Detail of regulatory assets |  |
Regulatory assets, current | 3,969 | 0
Regulatory assets, non-current | 462 | 2,942
Coal reclamation |  |
Detail of regulatory assets |  |
Regulatory assets, current | 418 | 418
Regulatory assets, non-current | 5,495 | 6,085
Other |  |
Detail of regulatory assets |  |
Regulatory assets, current | 0 | 5
Regulatory assets, non-current | $ 0 | $ 0

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- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
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