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

Credit Agreement

The Company has a $1,000,000 revolving credit facility that matures on August 23, 2021 (the "Credit Agreement"). The Credit Agreement bears interest at either (a) LIBOR plus a spread ranging from 1.00% to 1.75% or (b) Alternate Base Rate plus a spread ranging from 0.00% to 0.75% depending on the credit rating of the Company. At September 30, 2017, the Company had no borrowings outstanding under the Credit Agreement. As of September 30, 2017, the Company had outstanding letters of credit totaling $45,414 and borrowing availability of $954,586 under the Credit Agreement. As of September 30, 2017, the Company was in compliance with the total leverage ratio financial maintenance covenant.

3.60% Senior Notes due 2026 and 5.0% Senior Notes due 2046

In August 2016, the Company issued $750,000 aggregate principal amount of 3.60% senior notes due 2026 (the "3.60% 2026 Senior Notes") and $700,000 aggregate principal amount of 5.0% senior notes due 2046 (the "5.0% 2046 Senior Notes"). On March 27, 2017, the Company commenced registered exchange offers to exchange the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes for new notes that are identical in all material respects to the 3.60% 2026 Senior Notes and the 5.0% 2046 Senior Notes, except that the offer and issuance of the new SEC-registered notes have been registered under the Securities Act of 1933, as amended (the “Securities Act”). The exchange offers expired on April 24, 2017, and approximately 99.97% of the 3.60% 2026 Senior Notes and 100.00% of the 5.0% 2046 Senior Notes were exchanged. The 3.60% 2026 Senior Notes that were not exchanged pursuant to the exchange offers have not been registered under the Securities Act or any state securities laws and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements or a transaction not subject to the registration requirements of the Securities Act or any state securities law.

4.625% Senior Notes due 2021 and 4.875% Senior Notes due 2023

In September 2016, the Company issued $624,793 aggregate principal amount of 4.625% senior notes due 2021 (the “4.625% Westlake 2021 Senior Notes”) and $433,793 aggregate principal amount of 4.875% senior notes due 2023 (the “4.875% Westlake 2023 Senior Notes”) upon the closing of the Company's offers to exchange any and all of the $688,000 aggregate principal amount of the outstanding 4.625% senior notes due 2021 issued by Eagle Spinco Inc., a wholly-owned subsidiary of Axiall (“Eagle Spinco”), and the $450,000 aggregate principal amount of the outstanding 4.875% senior notes due 2023 issued by Axiall. In the exchange offers, $624,793 aggregate principal amount of 4.625% Westlake 2021 Senior Notes and $433,793 aggregate principal amount of 4.875% Westlake 2023 Senior Notes were issued by the Company, leaving outstanding $63,207 aggregate principal amount of the 4.625% 2021 senior notes (the "4.625% Subsidiary 2021 Senior Notes") and $16,207 aggregate principal amount of the 4.875% 2023 senior notes (the " 4.875% Subsidiary 2023 Senior Notes"). On March 27, 2017, the Company commenced registered exchange offers to exchange the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes for new SEC-registered notes that are identical in all material respects to the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes, except that the offer and issuance of the new notes have been registered under the Securities Act. The exchange offers expired on April 24, 2017, and 100.00% of both the 4.625% Westlake 2021 Senior Notes and the 4.875% Westlake 2023 Senior Notes were exchanged.

GO Zone Bonds

During September 2017, the Company directed the Louisiana Local Government Authority Environmental Facilities and Community Development Authority (the “Authority”) to optionally redeem in full $250,000 aggregate principal amount of the 2007 Series revenue bonds (the “GO Zone Bonds”) on November 1, 2017. The GO Zone Bonds were issued by the Authority in December 2007 under the Gulf Opportunity Zone Act of 2005 (GO Zone Act) for the benefit of the Company and were subject to optional redemption by the Authority upon the direction of the Company at any time on or after November 1, 2017 for 100% of the principal plus accrued interest. In connection with the redemption of the Go Zone Bonds, the Authority is required to cause the GO Zone Bonds trustee to surrender the 6 ¾% tax exempt senior notes due November 2032 to the Senior Notes trustee for cancellation. The Company used cash on hand to fund the redemption of the GO Zone Bonds.

As of September 30, 2017, the Company was in compliance with all of the covenants with respect to the Credit Agreement, 3.60% 2026 Senior Notes, 5.0% 2046 Senior Notes, 4.625% Westlake 2021 Senior Notes, 4.875% Westlake 2023 Senior Notes, 3.60% Senior Notes Due 2022, 6 ½% tax-exempt senior notes due 2029, the 6 ¾% tax-exempt senior notes due 2032, the 6 ½% 2035 GO Zone Senior Notes, the 6 ½% 2035 IKE Zone Senior Notes and the waste disposal revenue bonds.

Unamortized debt issuance costs on Long-term debt were $21,547 and $24,113 at September 30, 2017 and December 31, 2016, respectively.