Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2021

Fair Value Measurements [Abstract]

Fair Value, by Balance Sheet Grouping [Table Text Block]

	Assets and Liabilities at Fair Value as of September 30, 2021
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	92,118	$	—	$	—	$	92,118
Short-term investments	15,124		13,676		—		28,800
Total cash and cash equivalents and investments	$	107,242	$	13,676	$	—	$	120,918

	Assets and Liabilities at Fair Value as of December 31, 2020
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	126,263	$	—	$	—	$	126,263
Short-term investments	—		26,012		—		26,012
Total cash and cash equivalents and investments	$	126,263	$	26,012	$	—	$	152,275