Investment Securities Available-for-Sale (Tables)

12 Months Ended

Dec. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Investment [Table Text Block]

The amortized cost, gross unrealized holding gains and losses, and fair value of long-term and short-term investments by major security type and class of security were as follows as of December 31, 2019 and 2018 (in thousands):

	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Fair Value
As of December 31, 2019
Long-term investments:
Foreign deposits	$	3,323	$	—	$	—		$	3,323
Municipal bond	1,000		—		—			1,000
	$	4,323	$	—	$	—		$	4,323
Short-term investments:
U.S. Treasury securities	$	6,156	$	—	$	(1	)	$	6,155
Certificates of deposit	440		—		—			440
U.S. government funds	63,136		—		—			63,136
	$	69,732	$	—	$	(1	)	$	69,731
	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Fair Value
As of December 31, 2018
Long-term investments:
Foreign deposits	$	2,573	$	—	$	—		$	2,573
Municipal bond	1,000		—		(19		)	981
	$	3,573	$	—	$	(19	)	$	3,554
Short-term investments:
U.S. Treasury securities	$	6,645	$	—	$	(3	)	$	6,642
Certificates of deposit	437		—		—			437
U.S. government funds	47,477		—		—			47,477
	$	54,559	$	—	$	(3	)	$	54,556

Available-for-sale Securities [Table Text Block]

Maturities of debt securities classified as available-for-sale were as follows (in thousands):

	December 31, 2019
	Amortized Cost		Fair Value
Available-for-sale:
Due after one year through five years	$	4,323	$	4,323
	$	4,323	$	4,323