Discontinued Operations (Tables)

3 Months Ended

Mar. 31, 2017

Discontinued Operations and Disposal Groups [Abstract]

Disposal Groups, Including Discontinued Operations [Table Text Block]

Select financial information of discontinued operations is summarized below.

	Three months ended March 31,
($ in millions)	2017		2016
Pretax income	$	1	$	4
Tax expense	—		1