Segment And Geographic Information (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 customer	Dec. 31, 2011 customer	Dec. 31, 2010 customer
Segment Reporting Information [Line Items]
Number of segments	2
Number of plants	10
Olefins [Member]
Segment Reporting Information [Line Items]
Number of major customers	0	0	0
Proforma decrease in segment operating income loss		$ 29,813
Vinyls [Member]
Segment Reporting Information [Line Items]
Number of major customers	0	0	1
Maximum percentage of sales held by single customer			10.60%
Proforma increase in segment operating income loss		25,536
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Proforma increase in segment operating income loss		$ 4,277
PVC Joint Venture In China [Member]
Segment Reporting Information [Line Items]
Ownership interest	59.00%