Investments (Tables)

9 Months Ended

Sep. 30, 2017

The fair value of investments classified as short-term consists of the following:


	September 30, 2017		December 31, 2016
Available-for-sale investments:
Time deposits and certificates of deposit	$	21,503	$	23,818
Bankers’ acceptance drafts		3,452		1,439
Asset-backed securities		39,702		36,809
Commercial paper		21,215		24,381
Corporate obligations		80,099		46,707
Municipal bonds		45		591
Promissory note		1,075		675
U.S. treasury obligations		25,777		25,414
U.S. agency obligations		35,763		29,629

	$	228,631	$	189,463

Investments classified as long-term consists of the following:


	September 30, 2017		December 31, 2016
Available-for-sale investments:
Group insurance contracts	$	6,193	$	5,558
Cost method investments:
Minority interest in a private company⁽¹⁾		4,400		4,300

	$	10,593	$	9,858

⁽¹⁾	In April 2016, the Company invested $9,300 for a minority interest in a private company. For the year ended December 31, 2016, the Company recognized $5,000 of impairment charges related to this cost method investment. In July 2017, the Company invested an additional $100 in this private company.

The following tables show the gross unrealized gains and (losses) aggregated by investment category for available-for-sale investments:


	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
As of September 30, 2017:
Short-term investments:
Available-for-sale investments:
Time deposits and certificates of deposit	$	21,501	$	2	$	—		$	21,503
Bankers’ acceptance drafts		3,452		—		—			3,452
Asset-backed securities		39,709		17		(24	)		39,702
Commercial paper		21,278		—		(63	)		21,215
Corporate obligations		80,020		87		(8	)		80,099
Municipal bonds		45		—		—			45
Promissory note		1,075		—		—			1,075
U.S. treasury obligations		25,756		21		—			25,777
U.S. agency obligations		35,756		10		(3	)		35,763

	$	228,592	$	137	$	(98	)	$	228,631


	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
As of September 30, 2017:
Long-term investments:
Available-for-sale investments:
Group insurance contracts	$	6,193	$	—	$	—		$	6,193


	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
As of December 31, 2016:
Short-term investments:
Available-for-sale investments:
Time deposits and certificates of deposit	$	23,818	$	—	$	—		$	23,818
Bankers acceptance drafts		1,439		—		—			1,439
Asset-backed securities		36,847		6		(44	)		36,809
Commercial paper		24,423		—		(42	)		24,381
Corporate obligations		46,700		21		(14	)		46,707
Municipal bonds		591		—		—			591
Promissory note		675		—		—			675
U.S. treasury obligations		25,414		—		—			25,414
U.S. agency obligations		29,631		8		(10	)		29,629

	$	189,538	$	35	$	(110	)	$	189,463


	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
As of December 31, 2016:
Long-term investments:
Available-for-sale investments:
Group insurance contracts	$	6,276	$	—	$	(718	)	$	5,558