Fair Value Measurements (Details 1) - Nonrecurring Basis $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Properties, plant and equipment, net (held and used)	$ 0	$ 0
Properties, plant and equipment, net (held for sale)	212	212
Investments and advances	56	56
Total Assets at Fair Value	268	268
Properties, plant and equipment, net (held and used), Before-Tax Loss	0	0
Properties, plant and equipment, net (held for sale), Before-Tax Loss	290	586
Investments and advances, Before Tax Loss	43	44
Total Assets at Fair Value, Before-Tax Loss	333	630
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Properties, plant and equipment, net (held and used)	0	0
Properties, plant and equipment, net (held for sale)	0	0
Investments and advances	0	0
Total Assets at Fair Value	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Properties, plant and equipment, net (held and used)	0	0
Properties, plant and equipment, net (held for sale)	0	0
Investments and advances	0	0
Total Assets at Fair Value	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Properties, plant and equipment, net (held and used)	0	0
Properties, plant and equipment, net (held for sale)	212	212
Investments and advances	56	56
Total Assets at Fair Value	$ 268	$ 268