Subsequent Event (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended	12 Months Ended
	Jan. 27, 2016	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Subsequent Event [Line Items]
Restructuring charges			$ 4	$ (1)	$ 11
Productivity Initiative [Member] | Scenario, Forecast [Member]
Subsequent Event [Line Items]
Restructuring charges		$ 140
Restructuring charges per share (USD per share)		$ 0.05
Employee separation costs		$ 120
Other associated restructuring costs		$ 20
Productivity Initiative [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Annualized productivity savings	$ 300