Convertible Debt (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Schedule of Debt

The following table outlines the effective interest rate, contractually stated interest costs, and costs related to the amortization of issuance costs for the Company's 2015 convertible senior notes:

	Years Ended
	December 31,
	2017	2016	2015
Effective interest rate of 2015 convertible senior notes	NA	NA	4.50%
Contractually stated interest costs	NA	NA	$101
Amortization of interest costs	NA	NA	$7