Commitments and Contingent Liabilities (Impact of PPG Settlement Arrangement Including Change in Fair Value of Stock to be Transferred) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Change in fair value:
PPG stock	$ 35	$ (8)
Equity forward instrument	(36)	7
Accretion of asbestos liability	4	4
Asbestos settlement - net expense	$ 3	$ 3