Fair Value Of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Of Financial Instruments [Abstract]

Fair Value Of Long-Term Debt

	March 31, 2021				December 31, 2020
($ in millions)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Total debt	$	16,769	$	13,354	$	16,769	$	11,635