Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net operating loss carryforward	$ 50	$ 64
Credit carryforward	24	26
Accruals	64	53
Pension	76	79
Allowance for doubtful accounts	5	5
Inventories	13	11
Other	12	15
Deferred taxes assets—total	244	253
Property, plant and equipment	(948)	(906)
Intangibles	(148)	(154)
Turnaround costs	(20)	(8)
Basis difference—consolidated partnerships	(202)	(209)
Other	(27)	(18)
Deferred tax liabilities—total	(1,345)	(1,295)
Valuation allowance	(47)	(56)
Total net deferred tax liabilities	(1,148)	(1,098)
Balance sheet classifications
Noncurrent deferred tax asset	11	13
Noncurrent deferred tax liability	$ (1,159)	$ (1,111)