Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2017

Fair Value Disclosures [Abstract]

Valuation of Company's Assets and Liabilities Measured at Fair Value

The following table summarizes the valuation of the Company’s assets and liabilities measured at fair value as categorized based on the hierarchy described in Note 2.

	Level 1		Level 2			Level 3		Total
	(In thousands)
As of March 31, 2017
Money market funds	$	26,627	$	—		$	—	$	26,627
Securities available-for-sale
Corporate debt		—		140,309			—		140,309
Trading securities
Corporate debt		—		75,404			—		75,404
Mutual funds held in rabbi trust		—		2,846			—		2,846
Foreign currency forward position		—		(1,093	)		—		(1,093	)
Total	$	26,627	$	217,466		$	—	$	244,093
As of December 31, 2016
Money market funds	$	58,573	$	—		$	—	$	58,573
Securities available-for-sale
Corporate debt		—		118,870			—		118,870
Trading securities
Corporate debt		—		74,207			—		74,207
Mutual funds held in rabbi trust				1,327					1,327
Foreign currency forward position		—		(266	)		—		(266	)
Total	$	58,573	$	194,138		$	—	$	252,711

Summary of Foreign Currency Forward Contracts

A summary of the Company’s foreign currency forward position is as follows:

	As of
	March 31, 2017			December 31, 2016
	(In thousands)
Notional value	$	68,260		$	66,972
Fair value of notional		69,353			67,238
Fair value of the liability	$	(1,093	)	$	(266	)

Summary of Company's Investments

The following is a summary of the Company’s investments:

			Gross		Gross			Estimated
	Amortized		unrealized		unrealized			fair
	cost		gains		losses			value
	(In thousands)
As of March 31, 2017
Securities available-for-sale
Corporate debt	$	140,475	$	13	$	(179	)	$	140,309
Trading securities
Corporate debt		75,527		68		(191	)		75,404
Mutual funds held in rabbi trust		2,729		117		—			2,846
Total trading securities		78,256		185		(191	)		78,250
Total investments	$	218,731	$	198	$	(370	)	$	218,559
As of December 31, 2016
Securities available-for-sale
Corporate debt	$	119,073	$	13	$	(216	)	$	118,870
Trading securities
Corporate debt		74,394		47		(234	)		74,207
Mutual funds in rabbi trust		1,212		115		—			1,327
Total trading securities		75,606		162		(234	)		75,534
Total investments	$	194,679	$	175	$	(450	)	$	194,404

Summary of Fair Value of Investments Based upon Contractual Maturities

The following table summarizes the fair value of the investments based upon the contractual maturities:

	As of
	March 31, 2017		December 31, 2016
	(In thousands)
Less than one year	$	131,457	$	117,904
Due in 1 - 5 years		87,102		76,500
Total	$	218,559	$	194,404

Fair Values and Unrealized Losses on Investments

The following table provides fair values and unrealized losses on investments and by the aging of the securities’ continuous unrealized loss position as of March 31, 2017 and December 31, 2016:

	Less than Twelve Months					Twelve Months or More					Total
	Estimated		Gross			Estimated		Gross			Estimated		Gross
	fair		unrealized			fair		unrealized			fair		unrealized
	value		losses			value		losses			value		losses
	(In thousands)
As of March 31, 2017
Corporate debt	$	136,368	$	(369	)	$	900	$	(1	)	$	137,268	$	(370	)
As of December 31, 2016
Corporate debt	$	136,667	$	(449	)	$	2,000	$	(1	)	$	138,667	$	(450	)