Our obligations under debt arrangements consisted of the following:



	March 31, 2018						December 31, 2017
	Principal		Unamortized Discount and Debt Issuance Costs ⁽¹⁾		Net Value		Principal		Unamortized Discount and Debt Issuance Costs ⁽¹⁾		Net Value
Senior secured credit facility	$	1,279,000	$	—	$	1,279,000	$	1,099,200	$	—	$	1,099,200
5.750% senior unsecured notes due February 2021	—		—		—		145,170		1,303		143,867
6.750% senior unsecured notes due August 2022	750,000		15,257		734,743		750,000		16,077		733,923
6.000% senior unsecured notes due May 2023	400,000		5,424		394,576		400,000		5,691		394,309
5.625% senior unsecured notes due June 2024	350,000		5,493		344,507		350,000		5,717		344,283
6.500% senior unsecured notes due October 2025	550,000		9,157		540,843		550,000		9,462		540,538
6.250% senior unsecured notes due May 2026	450,000		7,920		442,080		450,000		8,002		441,998
Total long-term debt	$	3,779,000	$	43,251	$	3,735,749	$	3,744,370	$	46,252	$	3,698,118


(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 $13.1 million and $14.1 million as of March 31, 2018 and December 31, 2017, respectively.