Segment Information (Total Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 5,920,564	$ 5,569,285
Operating Segments [Member] | Olefins [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,130,028	1,869,888
Operating Segments [Member] | Vinyls [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	2,734,246	2,638,833
Corporate, Non-Segment [Member] | Corporate and Other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 1,056,290	$ 1,060,564