Quarterly Results (unaudited) (Tables)

12 Months Ended

Dec. 31, 2012

Quarterly Results (unaudited)

Schedule of quarterly results

($ in millions)		First Quarter				Second Quarter				Third Quarter				Fourth Quarter
		2012		2011		2012		2011		2012		2011		2012		2011
Revenues	$	1,052	$	1,125	$	1,065	$	1,141	$	970	$	1,279	$	1,116	$	1,114
Net income		83		91		98		135		103		160		142		83