Income Taxes Income Taxes (Schedule of Effective Tax Rate Reconciliation) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Line Items]
Income tax provision computed at US federal statutory tax rate	$ 329	$ 563	$ 112
Change in valuation allowance	49	89	29
Equity income and dividends	(50)	(44)	(31)
(Income) expense not resulting in tax impact, net	(34)ce_IncomeExpenseNotResultingInTaxImpact	(33)ce_IncomeExpenseNotResultingInTaxImpact	(39)ce_IncomeExpenseNotResultingInTaxImpact
US tax effect of foreign earnings and dividends	49	35	42
Foreign tax credits	(34)	(38)	(187)
Other foreign tax rate differentials	(33)	(55)	(2)
Legislative changes	0	(19)	0
Tax-deductible interest on foreign equity investments and other related items	12	11	11
State income taxes, net of federal benefit	9	11	4
Other, net	17	(12)	6
Income tax provision (benefit)	$ 314us-gaap_IncomeTaxExpenseBenefit	$ 508us-gaap_IncomeTaxExpenseBenefit	$ (55)us-gaap_IncomeTaxExpenseBenefit
Effective income tax rate	33.00%	32.00%	(17.00%)
UNITED STATES
Income Taxes [Line Items]
US federal statutory tax rate	35.00%

(Income) expense not resulting in tax impact.

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Income Tax Reconciliation, Equity Income and Dividends.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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