Supplemental Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Accrued Liabilities [Abstract]
Accrued liabilities	$ 552,581		$ 552,581		$ 287,313
Accrued rebates	73,798		73,798		$ 46,460
Other Income, Net [Abstract]
Interest income	537	$ 1,631	6,899	$ 3,383
Dividend income	868	0	5,142	3,328
Acquisition-related financing costs	(11,420)	0	(12,220)	0
Foreign exchange currency (losses) gains, net	(1,281)	(731)	(2,435)	1,140
Impairment of equity method investment	0	0	0	(4,925)
Gain realized on previously held shares of Axiall common stock	49,080	0	49,080	0
Gain on acquisition and related expenses, net	0	0	0	20,430
Gain from sales of equity securities	3,321	0	4,640	3,795
Other	160	1,736	985	6,639
Other income, net	$ 41,265	$ 2,636	$ 52,091	$ 33,790