Income Taxes (Net Operating Loss Carryforwards and Tax Credit Carryforwards Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Amount	$ 452
Tax Credit Carryforward, Valuation Allowance	164
Alternative Minimum Tax Credit Carryforwards, Before Tax	$ 21
Tax Credit Carryforward, Expiration Date	Dec. 31, 2027
US Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 35
State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	42
Valuation allowance offset for State net operating loss carryforwards due to uncertain recoverability	38
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	2,600
CHINA
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 473
Minimum [Member] | US Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward expiration	Dec. 31, 2021
Minimum [Member] | CHINA
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward expiration	Dec. 31, 2018
Maximum [Member] | CHINA
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward expiration	Dec. 31, 2022