Long-Term Debt (Tables)

9 Months Ended

Sep. 30, 2017

Debt Disclosure [Abstract]

Schedule Of Long-Term Debt

Long-term debt consists of the following:

	September 30, 2017							December 31, 2016
	Principal Amount		Unamortized Premium, Discount and Debt Issuance Costs			Net Long-term Debt		Principal Amount		Unamortized Premium, Discount and Debt Issuance Costs			Net Long-term Debt
Revolving credit facility	$	—	$	—		$	—	$	325,000	$	—		$	325,000
4.625% senior notes due 2021 (the    "4.625% Westlake 2021 Senior    Notes")	624,793		21,881			646,674		624,793		26,837			651,630
4.625% senior notes due 2021    (the "4.625% Subsidiary 2021 Senior    Notes")	63,207		2,343			65,550		63,207		2,862			66,069
3.60% senior notes due 2022	250,000		(1,635		)	248,365		250,000		(1,891		)	248,109
4.875% senior notes due 2023 (the    "4.875% Westlake 2023 Senior    Notes")	433,793		11,791			445,584		433,793		13,431			447,224
4.875% senior notes due 2023    (the "4.875% Subsidiary 2023 Senior    Notes")	16,207		477			16,684		16,207		540			16,747
3.60% senior notes due 2026    (the "3.60% 2026 Senior Notes")	750,000		(10,031		)	739,969		750,000		(10,757		)	739,243
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	100,000		(861		)	99,139		100,000		(916		)	99,084
6 ¾% tax-exempt senior notes due 2032	250,000		(605		)	249,395		250,000		(1,883		)	248,117
6 ½% tax-exempt senior notes due 2035    (the "6 ½% 2035 GO Zone Senior    Notes")	89,000		(806		)	88,194		89,000		(839		)	88,161
6 ½% tax-exempt senior notes due 2035    (the "6 ½% 2035 IKE Zone Senior    Notes")	65,000		(578		)	64,422		65,000		(602		)	64,398
5.0% senior notes due 2046 (the "5.0%    2046 Senior Notes")	700,000		(25,463		)	674,537		700,000		(26,017		)	673,983
Long-term debt, net	$	3,352,889	$	(3,487	)	$	3,349,402	$	3,677,889	$	765		$	3,678,654