Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2018

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, 2018 and 2017 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.



	2018				2017
	Carrying Value		Fair Value		Carrying Value		Fair Value
3.60% 2022 Senior Notes	$	249	$	248	$	249	$	255
3.60% 2026 Senior Notes	741		692		740		757
Loan related to tax-exempt waste disposal revenue bonds due 2027	11		11		11		11
6 ½% 2029 GO Zone Senior Notes	99		106		99		111
6 ½% 2035 GO Zone Senior Notes	88		95		88		99
6 ½% 2035 IKE Zone Senior Notes	65		69		65		74
5.0% 2046 Senior Notes	676		641		675		787
4.375% 2047 Senior Notes	491		417		491		518
3.50% 2032 GO Zone Refunding Senior Notes	248		233		248		256
4.625% Westlake 2021 Senior Notes ⁽¹⁾	—		—		645		639
4.625% Subsidiary 2021 Senior Notes ⁽¹⁾	—		—		65		65
4.875% Westlake 2023 Senior Notes	—		—		445		449
4.875% Subsidiary 2023 Senior Notes	—		—		16		16

___________________________


(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 8.