Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Measurements [Abstract]

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

	Assets and Liabilities at Fair Value as of March 31, 2021
	Level 1		Level 2		Level 3		Total
	(in thousands)
Assets
Cash and cash equivalents	$	97,652	$	—	$	—	$	97,652
Short-term investments	15,245		28,464		—		43,709
Total cash and cash equivalents and investments	$	112,897	$	28,464	$	—	$	141,361

	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