DEBT, CREDIT FACILITY, AND CAPITAL LEASE OBLIGATIONS (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Schedule of long-term debt instruments

The following table presents the components of Long-Term Debt, Net on the Consolidated Balance Sheets:

		Maturity Date	December 31,
($ in millions)	Interest Rate		2018		2017
Notes
2011 Notes	5.15%	2021	$	250	$	250
2012 Notes	3.85%	2023	150		150
2014 Notes	5.00%	2044	150		150
2015 Notes	3.05%	2025	300		300
2018 Notes	4.85%	2048	300		—
Tax-Exempt Local Furnishings Bonds
2010 Pima A	5.25%	2040	100		100
2012 Pima A	4.50%	2030	16		16
2013 Pima A	4.00%	2029	91		91
2013 Apache A (1)	2.42%	2032	—		100
Tax-Exempt Pollution Control Bonds
2009 Pima A	4.95%	2020	80		80
2009 Coconino A	5.13%	2032	15		15
2010 Coconino A (2)	2.34%	2032	—		37
2012 Apache A	4.50%	2030	177		177
Total Long-Term Debt (3)			1,629		1,466
Less Unamortized Discount and Debt Issuance Costs			14		12
Less Current Maturities of Long-Term Debt			—		100
Total Long-Term Debt, Net			$	1,615	$	1,354

⁽¹⁾  Variable rate debt for which rates were reset monthly. The weighted average interest rate was calculated based on a percentage of an index equal to one-month LIBOR plus a credit spread. The interest rate for 2018 was calculated through the redemption date.

⁽²⁾  Variable rate debt for which rates were reset weekly. The weighted average interest rate was calculated using a weighted average and includes LOC fees and remarketing fees. The interest rate for 2018 was calculated through the redemption date.

⁽³⁾  As of December 31, 2018, all of TEP's debt is unsecured.

Schedule of line of credit facilities

TEP's unsecured credit agreement with a maturity date of October 2022 included in Current Liabilities on the Consolidated Balance Sheets consists of the following:

	Capacity		Sub-Limit LOC		Borrowed		Available		Weighted Average Interest Rate		Pricing (1)
(in millions)	December 31, 2018
Credit Facility	$	250	$	50	$	—	$	250	—	%	LIBOR + 1.000	%	or ABR + 0.00%

(in millions)	December 31, 2017
Credit Facility	$	250	$	50	$	35	$	215	2.56	%	LIBOR + 1.000	%	or ABR + 0.00%

⁽¹⁾  Interest rates and fees under the credit facility are based on a pricing grid tied to TEP's credit rating.

Schedule of capital lease obligations

The following table details Capital Lease Obligations on the Consolidated Balance Sheets:

	December 31,
(in millions)	2018		2017
Gila River Unit 2	$	164	$	—
Springerville Common Facilities	29		39
Total Capital Lease Obligations	193		39
Less Current Portion	173		11
Total Capital Lease Obligations, Non-Current	$	20	$	28

Schedule of maturities of long-term debt

Long-term debt, including revolving credit facilities classified as long-term, and capital lease obligations mature on the following dates:

(in millions)	Long-Term Debt(1)		Capital Lease Obligations		Total Debt Maturities
2019	$	—	$	187	$	187
2020	80		20		100
2021	250		—		250
2022	—		—		—
2023	150		—		150
Total 2019 - 2023	480		207		687
Thereafter	1,149		—		1,149
Less: Imputed Interest	—		14		14
Total	$	1,629	$	193	$	1,822

⁽¹⁾  Total long-term debt excludes $11 million of related unamortized debt issuance costs and $3 million of unamortized original issue discount.