Pension and Postretirement Expense Level 4 (Details) - U.S. Pension Plan Investments Measured at Fair Value - Pension Plan [Member] - UNITED STATES - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Large Cap Equity Funds	$ 33	$ 38
Small mid Cap Equity Funds	5	6
Other International Equity	22	30
Debt Securities Fixed Income	102	116
Cash, Money Market and Other	3	6
Pension Benefits Fair Value of Plan Assets of Underfunded Plans	185	213
Fair value of plan assets at end of year subtotal	165	196
Other funds	20	17
Fair Value, Inputs, Level 1 [Member]
Large Cap Equity Funds	0	0
Small mid Cap Equity Funds	0	0
Other International Equity	0	0
Debt Securities Fixed Income	0	0
Cash, Money Market and Other	0	0
Pension Benefits Fair Value of Plan Assets of Underfunded Plans	0	0
Fair Value, Inputs, Level 2 [Member]
Large Cap Equity Funds	33	38
Small mid Cap Equity Funds	5	6
Other International Equity	22	30
Debt Securities Fixed Income	102	116
Cash, Money Market and Other	3	6
Pension Benefits Fair Value of Plan Assets of Underfunded Plans	165	196
Fair Value, Inputs, Level 3 [Member]
Large Cap Equity Funds	0	0
Small mid Cap Equity Funds	0	0
Other International Equity	0	0
Debt Securities Fixed Income	0	0
Cash, Money Market and Other	0	0
Pension Benefits Fair Value of Plan Assets of Underfunded Plans	$ 0	$ 0