Debt

Our obligations under debt arrangements consisted of the following:



	September 30, 2017						December 31, 2016
	Principal		Unamortized Discount and Debt Issuance Costs ⁽¹⁾		Net Value		Principal		Unamortized Discount and Debt Issuance Costs (1)		Net Value
Senior secured credit facility	$	1,372,500	$	—	$	1,372,500	$	1,278,200	$	—	$	1,278,200
5.750% senior unsecured notes due February 2021	350,000		3,399		346,601		350,000		4,163		345,837
6.750% senior unsecured notes due August 2022	750,000		16,889		733,111		750,000		19,296		730,704
6.000% senior unsecured notes due May 2023	400,000		5,958		394,042		400,000		6,758		393,242
5.625% senior unsecured notes due June 2024	350,000		5,941		344,059		350,000		6,614		343,386
6.500% senior unsecured notes due October 2025	550,000		9,764		540,236		—		—		—
Total long-term debt	$	3,772,500	$	41,951	$	3,730,549	$	3,128,200	$	36,831	$	3,091,369


(1)	Unamortized debt issuance costs associated with our senior secured credit facility (included in Other Long Term Assets on the Unaudited Condensed Consolidated Balance Sheet) were $15.2 million and $10.7 million as of September 30, 2017 and December 31, 2016, respectively.

As of September 30, 2017, we were in compliance with the financial covenants contained in our credit agreement and senior unsecured notes indentures.

Senior Secured Credit Facility

In July 2017, we amended our credit agreement to, among other things, make certain technical amendments related to the financing of our acquisition of the Alkali Business.

The key terms for rates under our $1.7 billion senior secured credit facility, which are dependent on our leverage ratio (as defined in the credit agreement), are as follows:

•The applicable margin varies from 1.50% to 3.00% on Eurodollar borrowings and from 0.50% to 2.00% on alternate base rate borrowings.

•Letter of credit fees range from 1.50% to 3.00%

•The commitment fee on the unused committed amount will range from 0.25% to 0.50%.

•The accordion feature is $300.0 million, giving us the ability to expand the size of the facility to up to $2.0 billion for acquisitions or growth projects, subject to lender consent.

At September 30, 2017, we had $1.4 billion borrowed under our $1.7 billion credit facility, with $38.7 million of the borrowed amount designated as a loan under the inventory sublimit. Our credit agreement allows up to $100.0 million of the capacity to be used for letters of credit, of which $12.8 million was outstanding at September 30, 2017. Due to the revolving nature of loans under our credit facility, additional borrowings and periodic repayments and re-borrowings may be made until the maturity date. The total amount available for borrowings under our credit facility at September 30, 2017 was $314.7 million.

Senior Unsecured Note Issuance

On August 14, 2017, we issued $550 million in aggregate principal amount of 6.50% senior unsecured notes due October 1, 2025. Interest payments are due April 1 and October 1 of each year with the initial interest payment due April 1, 2018. That issuance generated net proceeds of $540.1 million, net of issuance costs incurred. The net proceeds were used to fund a portion of the purchase price for our acquisition of the Alkali Business.