Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2020

Fair Value Disclosures [Abstract]

Schedule of Carrying Amounts and Estimated Fair Values

The carrying amounts and estimated fair values, based on Level 1 inputs, of long-term debt consisted of the following:

	June 30, 2020				December 31, 2019
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	($ in millions)
Long-term debt, including current maturities	$	(12,697)	$	(16,362)	$	(12,196)	$	(14,806)