Fair Value Of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Of Financial Instruments [Abstract]

Fair Value Of Long-Term Debt

	March 31, 2020				December 31, 2019
($ in millions)		Carrying Amount		Fair Value		Carrying Amount		Fair Value
Total debt	$	17,511	$	10,117	$	17,516	$	12,026