Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2017

Schedule Of Carrying And Fair Values Of Long-Term Debt

The carrying and fair values of the Company's long-term debt (including the current portion of long-term debt) at December 31, 2017 and 2016 are summarized in the table below. The Company's long-term debt instruments are publicly-traded. A market approach, based upon quotes from financial reporting services, is used to measure the fair value of the Company's long-term debt. 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.



	2017				2016
	Carrying Value		Fair Value		Carrying Value		Fair Value
Revolving credit facility	$	—	$	—	$	325	$	325
4.625% Westlake 2021 Senior Notes ⁽¹⁾	645		639		652		651
4.625% Subsidiary 2021 Senior Notes ⁽¹⁾	65		65		66		66
3.60% 2022 Senior Notes	249		255		248		252
4.875% Westlake 2023 Senior Notes	445		449		447		451
4.875% Subsidiary 2023 Senior Notes	16		16		17		17
3.60% 2026 Senior Notes	740		757		739		722
Loan related to tax-exempt waste disposal revenue bonds due 2027	11		11		11		11
6 ½% 2029 GO Zone Senior Notes	99		111		99		112
6 ¾% 2032 GO Zone Senior Notes	—		—		248		259
6 ½% 2035 GO Zone Senior Notes	88		99		88		100
6 ½% 2035 IKE Zone Senior Notes	65		74		65		73
5.0% 2046 Senior Notes	675		787		674		692
4.375% 2047 Senior Notes	491		518		—		—
3.50% 2032 Senior Notes	248		256		—		—

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(1)	The 4.625% Westlake 2021 Senior Notes and 4.625% Subsidiary 2021 Senior Notes were classified as a component of current liabilities in the consolidated balance sheet at December 31, 2017. For additional information, see Note 9.