Investments (Tables)

9 Months Ended

Sep. 30, 2014

Investments, Debt and Equity Securities [Abstract]

Fair Value of Short-Term Available-for-Sale and Trading Investments

The fair value of short-term investments with maturities or estimated lives of less than one year consists of the following:

	September 30, 2014		December 31, 2013
Available-for-sale investments:
Bankers’ acceptance drafts	$	765	$	491
Time deposits and certificates of deposit		40,672		64,989
Commercial paper		9,691		53,434
Corporate obligations		14,890		18,351
Municipal bonds		2,099		—
U.S. agency obligations		71,925		162,450
	$	140,042	$	299,715
Trading investments:
Mutual funds		—		1,000
	$	140,042	$	300,715

Fair Value of Long-Term Available-for-Sale Investments

The fair value of long-term investments with maturities of more than one year consists of the following:

	September 30, 2014		December 31, 2013
Available-for-sale investments:
Time deposits and certificates of deposit	$	50	$	54
Asset-backed securities		63,986		—
Corporate obligations		61,446		—
Municipal bonds		1,257		—
U.S. agency obligations		8,010		60,351
	$	134,749	$	60,405

Gross Unrealized Gains and (Losses) Aggregated by Investment Category Short-Term and Long-Term Securities

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

As of September 30, 2014:	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
Short-term investments:
Bankers’ acceptance drafts	$	765	$	—	$	—		$	765
Time deposits and certificates of deposit		40,672		1		(1	)		40,672
Commercial paper		9,692		2		(3	)		9,691
Corporate obligations		14,889		1		—			14,890
Municipal bonds		2,100		—		(1	)		2,099
U.S. agency obligations		71,879		46		—			71,925
	$	139,997	$	50	$	(5	)	$	140,042
Long-term investments:
Time deposits	$	50	$	—	$	—		$	50
Asset-backed securities		64,039		12		(65	)		63,986
Corporate obligations		61,496		13		(63	)		61,446
Municipal bonds		1,260		—		(3	)		1,257
U.S. agency obligations		8,011		—		(1	)		8,010
	$	134,856	$	25	$	(132	)	$	134,749

As of December 31, 2013:	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
Short-term investments:
Bankers’ acceptance drafts	$	491	$	—	$	—		$	491
Time deposits and certificates of deposit		64,983		10		(4	)		64,989
Commercial paper		53,429		5		—			53,434
Corporate obligations		18,360		—		(9	)		18,351
U.S. agency obligations		162,430		22		(2	)		162,450
	$	299,693	$	37	$	(15	)	$	299,715
Long-term investments:
Time Deposits	$	54	$	—	$	—		$	54
U.S. agency obligations		60,374		9		(32	)		60,351
	$	60,428	$	9	$	(32	)	$	60,405