Common Costs Charged to Related Parties - Common Cost Allocations

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- Definition

Intercompany Allocation Parent to Subsidiary

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No definition available.

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- Definition

management fee

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- Definition

Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer.

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- Definition

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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Reflects the sum of all other revenue and income realized from sales and other transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party during the period.

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Amount of selling, general and administrative expenses resulting from transactions, excluding transactions that are eliminated in consolidated or combined financial statements, with related party.

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- Definition

Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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RELATED PARTY TRANSACTIONS (Receivables From/To and Goods and Services Provided By/To) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Related Party Transaction, Due to/from Related Party [Abstract]
Due from related parties	$ 6,000		$ 6,000		$ 7,000
Due to related parties	3,000		3,000		4,000
Supplemental workforce	183,146	$ 131,776	391,898	$ 327,659
Transmission Revenues, UNS Electric
Related Party Transaction, Due to/from Related Party [Abstract]
Revenue from related party	2,000	2,000	5,000	5,000
Wholesale Revenue, UNS Electric
Related Party Transaction, Due to/from Related Party [Abstract]
Revenue from related party	1,000	0	1,000	0
Control Area Services, UNS Electric
Related Party Transaction, Due to/from Related Party [Abstract]
Control area services	1,000	1,000	2,000	2,000
Common Costs, UNS Energy Affiliates
Related Party Transaction, Due to/from Related Party [Abstract]
Common costs	4,000	4,000	13,000	12,000
Supplemental Workforce, SES
Related Party Transaction, Due to/from Related Party [Abstract]
Supplemental workforce	4,000	4,000	11,000	11,000
Corporate Services, UNS Energy
Related Party Transaction, Due to/from Related Party [Abstract]
Corporate services	2,000	1,000	$ 5,000	4,000
Massachusetts Formula - TEP's allocation (percentage)			82.00%
Management fee	1,000	1,000	$ 4,000	3,000
Corporate Services, UNS Energy Affiliates
Related Party Transaction, Due to/from Related Party [Abstract]
Corporate services	2,000	$ 1,000	5,000	$ 3,000
UNS Electric
Related Party Transaction, Due to/from Related Party [Abstract]
Due from related parties	4,000		4,000		5,000
Due to related parties	0		0		0
UNS Gas
Related Party Transaction, Due to/from Related Party [Abstract]
Due from related parties	1,000		1,000		2,000
Uns Energy
Related Party Transaction, Due to/from Related Party [Abstract]
Due from related parties	1,000		1,000		0
Due to related parties	1,000		1,000		1,000
SES
Related Party Transaction, Due to/from Related Party [Abstract]
Due to related parties	$ 2,000		$ 2,000		$ 3,000