Segment And Geographic Information (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting Information [Line Items]
Number of segments	2
Number of plants	10
Olefins [Member]
Segment Reporting Information [Line Items]
Number of customers that account for more than 10% of sales	0	0	0
Maximum percentage of sales held by single customer	10.00%	10.00%	10.00%
Proforma decrease in segment operating income loss		$ 29,813
Proforma increase in segment operating income loss			2,979
Vinyls [Member]
Segment Reporting Information [Line Items]
Number of customers that account for more than 10% of sales	0	1	0
Maximum percentage of sales held by single customer	10.00%	10.60%	10.00%
Proforma decrease in segment operating income loss			2,847
Proforma increase in segment operating income loss		25,536
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Proforma decrease in segment operating income loss			132
Proforma increase in segment operating income loss		$ 4,277
PVC Joint Venture In China [Member]
Segment Reporting Information [Line Items]
Ownership interest	59.00%