Fair Value of Financial Instruments (Unaudited) (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Fair value information of assets and liabilities measured at fair value on a recurring basis

The following table presents the financial assets and liabilities the company records at fair value on a recurring basis identified by the level of inputs used to determine fair value:

	March 31, 2020								December 31, 2019
$ in millions	Level 1		Level 2			Total			Level 1		Level 2			Total
Financial Assets (Liabilities)
Marketable securities	$	288	$	4		$	292		$	364	$	1		$	365
Marketable securities valued using NAV						16								17
Total marketable securities	288		4			308			364		1			382
Derivatives	—		(3		)	(3		)	—		(3		)	(3		)