Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Schedule of Carrying Amounts and Estimated Fair Values of Long-term Debt, Excluding Capital Lease Obligations, and Input Level to Determine Fair Values

The following table presents the carrying amounts and estimated fair values of our financial liabilities as of June 30, 2021 and December 31, 2020:

		June 30, 2021			December 31, 2020
	Input Level	Carrying Amount		Fair Value	Carrying Amount	Fair Value
		(Dollars in millions)
Long-term debt, excluding finance lease and other obligations	2	$	30,848	32,085	31,542	33,217
Interest rate swap contracts (see Note 10)	2	$	67	67	107	107