Cash, Cash Equivalents, and Investments (Tables)

12 Months Ended

Dec. 31, 2015

Cash and Cash Equivalents [Abstract]

Components of Cash, Cash Equivalents and Investments

Cash, cash equivalents, and investments consisted of the following (in thousands):



	December 31,
	2015		2014
Cash	$	45,951	$	54,917
Money market instruments	6,024		777
Cash and cash equivalents	51,975		55,694
Treasury bills	109,360		—
Asset-backed securities	61,994		1,311
Corporate bonds	54,376		30,889
Euro liquidity fund	47,730		48,235
Sovereign bonds	21,440		—
Agency bonds	978		6,883
Municipal bonds	590		1,237
Supranational bonds	—		1,901
Short-term investments	296,468		90,456
Corporate bonds	176,575		216,294
Treasury bills	44,437		90,412
Asset-backed securities	24,582		62,556
Sovereign bonds	13,503		13,461
Agency bonds	8,180		9,566
Municipal bonds	4,869		6,600
Limited partnership interest (accounted for using cost method)	942		1,956
Long-term investments	273,088		400,845
	$	621,531	$	546,995

Summary of Available-for-Sale Investments

The following table summarizes the Company’s available-for-sale investments as of December 31, 2015 (in thousands):



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Short-term:
Treasury bills	$	109,462	$	2	$	(104	)	$	109,360
Asset-backed securities	62,101		—		$	(107	)	$	61,994
Corporate bonds	54,420		22		(66		)	54,376
Euro liquidity fund	47,667		63		—			47,730
Sovereign bonds	21,466		—		(26		)	21,440
Agency bonds	979		—		(1		)	978
Municipal bonds	590		—		—			590
Long-term:
Corporate bonds	177,748		50		(1,223		)	$	176,575
Treasury bills	44,585		—		(148		)	$	44,437
Asset-backed securities	24,633		2		(53		)	24,582
Sovereign bonds	13,574		—		(71		)	13,503
Agency bonds	8,199		—		(19		)	8,180
Municipal bonds	4,849		20		—			4,869
	$	570,273	$	159	$	(1,818	)	$	568,614

Gross Unrealized Losses and Fair Value for Available-for-Sale Investments

The following table summarizes the Company’s gross unrealized losses and fair values for available-for-sale investments in an unrealized loss position as of December 31, 2015 (in thousands):



	Unrealized Loss Position For Less than 12 Months					Unrealized Loss Position For Greater than 12 Months					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Corporate bonds	$	162,714	$	(1,092	)	$	24,946	$	(197	)	$	187,660	$	(1,289	)
Treasury bills	127,203		(252		)	—		—			127,203		(252		)
Asset-backed securities	77,165		(154		)	1,783		(6		)	78,948		(160		)
Sovereign bonds	34,943		(97		)	—		—			34,943		(97		)
Agency bonds	9,158		(20		)	—		—			9,158		(20		)
	$	411,183	$	(1,615	)	$	26,729	$	(203	)	$	437,912	$	(1,818	)

Effective Maturity Dates of Available-for-Sale Investments

The following table presents the effective maturity dates of the Company’s available-for-sale investments as of December 31, 2015 (in thousands):



	<1 Year		1-2 Years		2-3 Years		3-4 Years		4-5 Years		5-7 Years		Total
Corporate bonds	$	54,376	$	87,025	$	74,069	$	13,280	$	2,201	$	—	$	230,951
Treasury bills	109,360		19,489		24,948		—		—		—		153,797
Asset-backed securities	61,994		2,491		14,443		3,294		3,960		394		86,576
Euro liquidity fund	47,730		—		—		—		—		—		47,730
Sovereign bonds	21,440		11,026		2,477		—		—		—		34,943
Agency bonds	978		4,894		3,286		—		—		—		9,158
Municipal bonds	590		4,869		—		—		—		—		5,459
	$	296,468	$	129,794	$	119,223	$	16,574	$	6,161	$	394	$	568,614