Investments (Tables)

3 Months Ended

Mar. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Summary of amortized cost and gross unrealized losses on all securities

	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
	(in thousands)
Short-term investments:
U.S. Treasury securities	$	14,416	$	—	$	—		$	14,416
Common stock		1,813		—		(19	)	$	1,794
Total short-term investments	$	16,229	$	—	$	(19	)	$	16,210

	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
	(in thousands)
Short-term investments:
U.S. Treasury securities	$	14,357		—		(1	)		14,356
Total short-term investments	$	14,357	$	—	$	(1	)	$	14,356

Summary of financial assets measured at fair value on a recurring basis

	Level 1		Level 2		Level 3		Total
	(in thousands)
Cash equivalents:
Money market funds	$	3,091	$	—	$	—	$	3,091
Investments:
Available-for-sale securities — current:
U.S. Treasury securities		—		14,416		—		14,416
Common stock		1,794		—		—		1,794
Total	$	4,885	$	14,416	$	—	$	19,301

	Level 1		Level 2		Level 3		Total
	(in thousands)
Cash equivalents:
Money market funds	$	2,821	$	—	$	—	$	2,821
Investments:
Available-for-sale securities — current:
U.S. Treasury securities		—		14,356		—		14,356
Total	$	2,821	$	14,356	$	—	$	17,177