Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Summary of Change in Level 3 Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table shows the change in Level 3 assets and liabilities measured at fair value on a recurring basis for the three months ended March 31, 2018 and the year ended December 31, 2017:

	Derivative asset embedded conversion feature (in thousands)
Balance, January 1, 2017	$	80,651
Gain on change in fair value		28,242
Reclassification of derivative asset to equity		(108,893	)
Balance, December 31, 2017 and March 31, 2018	$	—