REVENUE (Tables)

12 Months Ended

Dec. 31, 2018

Revenue from Contract with Customer [Abstract]

Disaggregation of revenue

The following table presents the disaggregation of TEP’s Operating Revenues on the Consolidated Statements of Income by type of service:

	Years Ended December 31,
(in millions)	2018		2017		2016
Retail	$	1,022	$	1,017	$	969
Wholesale	238		152		106
Other Services	100		103		109
Revenues from Contracts with Customers	1,360		1,272		1,184
Alternative Revenues	28		24		20
Other	45		45		31
Total Operating Revenues	$	1,433	$	1,341	$	1,235