Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2017

Summary Of Assets And Liabilities Accounted At Fair Value On A Recurring Basis

The following tables summarize, by level within the fair value hierarchy, the Company's assets and liabilities that were accounted for at fair value on a recurring basis:



	September 30, 2017
	Level 1			Level 2			Total
Derivative instruments
Risk management assets—Commodity forward contracts	$	233		$	12,183		$	12,416
Risk management liabilities—Commodity forward contracts	(6,183		)	(1,435		)	(7,618		)

	December 31, 2016
	Level 1			Level 2			Total
Derivative instruments
Risk management assets—Commodity forward contracts	$	878		$	14,108		$	14,986
Risk management liabilities—Commodity forward contracts	(6,854		)	(367		)	(7,221		)

Summary Of Carrying And Fair Values Of Long-Term Debt

The carrying and fair values of the Company's long-term debt are summarized in the table below. The fair value of the Company's long-term debt instruments is determined using a market approach, based upon quotes from financial reporting services. Because the Company's long-term debt instruments may not be actively traded, the inputs used to measure the fair value of the Company's long-term debt are classified as Level 2 inputs within the fair value hierarchy.



	September 30, 2017				December 31, 2016
	Carrying Value		Fair Value		Carrying Value		Fair Value
Revolving credit facility	$	—	$	—	$	325,000	$	325,000
4.625% Westlake 2021 Senior Notes	646,674		646,486		651,630		650,847
4.625% Subsidiary 2021 Senior Notes	65,550		62,983		66,069		65,775
3.60% senior notes due 2022	248,365		255,733		248,109		251,725
4.875% Westlake 2023 Senior Notes	445,584		452,004		447,224		451,301
4.875% Subsidiary 2023 Senior Notes	16,684		16,842		16,747		16,501
3.60% 2026 Senior Notes	739,969		749,570		739,243		722,055
Loan related to tax-exempt waste disposal revenue bonds due 2027	10,889		10,889		10,889		10,889
6 ½% tax-exempt senior notes due 2029	99,139		113,789		99,084		112,433
6 ¾% tax-exempt senior notes due 2032	249,395		251,250		248,117		258,818
6 ½% 2035 GO Zone Senior Notes	88,194		100,936		88,161		100,323
6 ½% 2035 IKE Zone Senior Notes	64,422		73,908		64,398		73,270
5.0% 2046 Senior Notes	674,537		760,739		673,983		691,712