Long-Term Debt	3 Months Ended
Mar. 31, 2019
Debt Disclosure [Abstract]
Long-Term Debt	7. Long-Term Debt Fair Value of Long-Term Debt At March 31, 2019, TEC’s long-term debt had a carrying amount of $2,575 million and an estimated fair market value of $2,749 million. At December 31, 2018, TEC’s total long-term debt had a carrying amount of $2,575 million and an estimated fair market value of $2,686 million. The fair value of the debt securities is determined using Level 2 measurements (see Note 13 for information regarding the fair value hierarchy).

The entire disclosure for long-term debt.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-URI http://asc.fasb.org/topic&trid=2208564

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