Income Taxes (Reconciliation Of Taxes Computed At The Statutory Rate To Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Provision for federal income tax, at statutory rate	$ 280	$ 378	$ 195
State income tax provision, net of federal income tax effect	28	26	1
Foreign income tax rate differential	5	(33)	(8)
Manufacturing deduction	0	(23)	(2)
Depletion	(4)	(7)	(2)
Noncontrolling interests	(6)	(9)	(7)
Tax on previously held shares of Axiall Corporation and certain other acquisition related items	0	0	(13)
Tax Act related adjustment	0	(591)	0
Changes in state apportionment and other state adjustments	(6)	2	(17)
Research and development expenditures and adjustments related to prior years' tax returns	(1)	(1)	(8)
Other, net	4	0	(1)
Provision for (benefit from) income taxes	$ 300	$ (258)	$ 138