Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Financial Assets Measured at Fair Value on Recurring Basis

The following table summarizes our financial assets measured at fair value on a recurring basis as of March 31, 2018 (in thousands):

			Fair Value Measurements
	Carrying Amount as of		As of March 31, 2018
	March 31, 2018		Level 1		Level 2		Level 3
Cash equivalents	$	8,169	$	8,169	$	—	$	—
3.25% Convertible senior notes due in 2020		23,490		—		—		23,490

			Fair Value Measurements
	Carrying Amount as of		As of December 31, 2017
	December 31, 2017		Level 1		Level 2		Level 3
Cash equivalents	$	13,718	$	13,718	$	—	$	—
3.25% Convertible senior notes due in 2020		22,469		—		—		22,469

Reconciliation of Beginning and Ending Balances of Assets Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)

The following table provides a reconciliation of the beginning and ending balances of assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) (in thousands):

	2018
Balance at January 1, 2018	$	22,469
Change in fair value		1,021
Balance at March 31, 2018	$	23,490