Convertible Senior Notes and Interest Expense (Tables)

3 Months Ended

Mar. 31, 2019

Debt Disclosure [Abstract]

Components of the Interest Expense Recognized

The following table sets forth the components of interest expense recognized in the accompanying Condensed Consolidated Statements of Operations for the 2013 Convertible Notes: 

	Three months ended March 31, 2018
Stated coupon interest expense	$	279
Amortization of debt issuance costs	61
Accretion of debt discount	533
Total	$	873
Effective interest rate	8.4		%