Organization Review Costs by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	$ 11	$ 17
Specialty [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	3	4
Commercial [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	7	12
International [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	0	0
Life and Group Non-Core [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	1	1
Corporate and Other Non-Core [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	$ 0	$ 0