At December 31,

2017

2016

Convertible Notes

$

172,500

$

172,500

Unaccreted discount on Convertible Notes

(11,677)

(17,149)

Unamortized issuance costs on Convertible Notes

(1,833)

(2,776)

Convertible Notes carrying value

$

158,990

$

152,575

Term Notes

$

 —

$

142,000

Unamortized issuance costs on Term Notes

 —

(3,665)

Term Notes carrying value

$

 —

$

138,335

Revolving credit facility balance

$

81,168

$

 —