Retirement Plans and Profit Sharing Arrangements (Amounts recognized in Balance Sheet) (Details 3) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Pension Plans [Member]
Amounts recognized in the Consolidated Balance Sheets
Benefit liability	$ (253)	$ (271)
Benefit asset	6	0
Net amount recognized	(247)	(271)
Other Postretirement Benefits Plan [Member]
Amounts recognized in the Consolidated Balance Sheets
Benefit liability	(15)	(15)
Benefit asset	0	0
Net amount recognized	$ (15)	$ (15)