Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2017

Fair Value of Financial Instruments

Schedule of major categories of assets and liabilities measured at fair value on a recurring basis

	September 30, 2017
	Level 1		Level 2		Level 3		Total
	(In thousands)
Financial Assets:
Money market accounts	$	227,502	$	—	$	—	$	227,502
Total financial assets	$	227,502	$	—	$	—	$	227,502

	December 31, 2016
	Level 1		Level 2		Level 3		Total
	(In thousands)
Financial Assets:
Money market accounts	$	58,320	$	—	$	—	$	58,320
Total financial assets	$	58,320	$	—	$	—	$	58,320

Rollforward of fair value of Level 3 instruments

	Level 3
	(In thousands)
Financial Liabilities
Balance at beginning of period — December 31, 2016	$	—
Issuance of convertible notes derivative		—
Balance — March 31, 2017		—
Issuance of convertible notes derivative		15,429
Change in fair value of derivative		(2,567)
Balance — June 30, 2017		12,862
Change in fair value of derivative at settlement		(3,453)
Settlement of convertible notes		(9,409)
Balance at end of period — September 30, 2017	$	—