Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2018

Fair Value Measurements

Schedule of Company's assets and liabilities by level within the fair value hierarchy

	September 30, 2018
	Fair Value Measurements
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash equivalents:
Money market funds, U.S. Government Securities and Agency Investments	$	131,654	$	—	$	—	$	131,654

	December 31, 2017
	Fair Value Measurements
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash equivalents:
Money market funds, U.S. Government Securities and Agency Investments	$	116,433	$	—	$	—	$	116,433