Quarterly Results (unaudited)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Quarterly Results (unaudited)

Quarterly Results (unaudited)

($ in millions)	First Quarter				Second Quarter				Third Quarter				Fourth Quarter
	2019		2018		2019		2018		2019		2018		2019		2018
Revenues	$	816	$	736	$	814	$	783	$	742	$	787	$	781	$	541
Net income (loss)	164		90		157		134		80		193		129		(52		)