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		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Change in fair value:
PPG stock	$ (75)	$ (18)	$ (78)	$ 10
Equity forward instrument	75	18	76	(11)
Accretion of asbestos liability	3	3	11	10
Asbestos settlement - net expense	$ 3	$ 3	$ 9	$ 9