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Asset Purchase Agreement, Site Contingency, Increase in Loss Exposure Not Accrued, Best Estimate

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Guarantor Obligations, Number of Parental Guarantees

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- Definition

Industry Litigation, Period to Complete Rulemaking Proceeding

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- Definition

Represents the percentage of share of the cost of control acquired by the entity.

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- Definition

Surety Bonds Expiring, Amount

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Best estimate of the loss exposure for reasonably possible environmental contingencies at an individual site for which no accrual has been recorded.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 10
-Subparagraph (c),(d)(2)
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859

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Commitments and Contingencies - Environmental Matters and Financial Assurances (Details) $ in Millions			3 Months Ended
	Jul. 06, 2016 guarantee	Jun. 24, 2016	Mar. 31, 2017 USD ($)
Arizona Public Service Company \| Letter of Credit Expiring in 2016 and 2017
Financial Assurances
Outstanding letters of credit			$ 35
Arizona Public Service Company \| Letters of Credit Expiring in 2017
Financial Assurances
Surety bonds expiring, amount			$ 61
4C Acquisition, LLC \| Four Corners Units 4 and 5
Environmental Matters
Percentage of share of cost of control			7.00%
Regional Haze Rules \| Arizona Public Service Company \| Four Corners Units 4 and 5
Environmental Matters
Percentage of share of cost of control			63.00%
Expected environmental cost			$ 400
Regional Haze Rules \| Arizona Public Service Company \| Natural gas tolling contract obligations \| Four Corners Units 4 and 5
Environmental Matters
Additional percentage share of cost of control			7.00%
Regional Haze Rules \| Arizona Public Service Company \| Four Corners \| Four Corners Units 4 and 5
Environmental Matters
Site contingency increase in loss exposure not accrued, best estimate			$ 45
Regional Haze Rules \| Arizona Public Service Company \| Navajo Plant
Environmental Matters
Expected environmental cost			200
Regional Haze Rules \| Arizona Public Service Company \| Cholla
Environmental Matters
Expected environmental cost			100
Coal combustion waste \| Arizona Public Service Company \| Four Corners
Environmental Matters
Site contingency increase in loss exposure not accrued, best estimate			15
Coal combustion waste \| Arizona Public Service Company \| Navajo Plant
Environmental Matters
Site contingency increase in loss exposure not accrued, best estimate			1
Coal combustion waste \| Arizona Public Service Company \| Navajo Plant \| Boron Inclusion on List of Groundwater Constituents
Environmental Matters
Industry litigation, period to complete rulemaking proceeding		3 years
Payment Guarantee
Financial Assurances
Number of parental guarantees \| guarantee	2
Minimum \| Coal combustion waste \| Arizona Public Service Company \| Cholla
Environmental Matters
Site contingency increase in loss exposure not accrued, best estimate			5
Maximum \| Coal combustion waste \| Arizona Public Service Company \| Cholla
Environmental Matters
Site contingency increase in loss exposure not accrued, best estimate			$ 40