Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2016

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 June 30, 2016
Money market funds	$	36,970	$	—	$	—	$	36,970
Securities available-for-sale
Corporate debt		—		72,650		—		72,650
Trading securities
Corporate debt		—		72,396		—		72,396
Mutual funds held in rabbi trust		—		1,284		—		1,284
Foreign currency forward position		—		5,518		—		5,518
Total	$	36,970	$	151,848	$	—	$	188,818
As of December 31, 2015
Money market funds	$	61,913	$	—	$	—	$	61,913
Securities available-for-sale
Corporate debt		—		82,671		—		82,671
Municipal securities		—		2,035		—		2,035
Foreign currency forward position		—		354		—		354
Total	$	61,913	$	85,060	$	—	$	146,973

Summary of Foreign Currency Forward Contracts

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

	As of
	June 30, 2016		December 31, 2015
	(In thousands)
Notional value	$	58,463	$	45,716
Fair value of notional		52,945		45,362
Fair value of the asset	$	5,518	$	354

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 June 30, 2016
Securities available-for-sale
Corporate debt	$	72,558	$	116	$	(24	)	$	72,650
Total securities available-for-sale		72,558		116		(24	)		72,650
Trading securities
Corporate debt		72,119		292		(15	)		72,396
Mutual funds held in rabbi trust		1,167		117		—			1,284
Total trading securities		73,286		409		(15	)		73,680
Total investments	$	145,844	$	525	$	(39	)	$	146,330
As of December 31, 2015
Securities available-for-sale
Corporate debt	$	82,937	$	4	$	(270	)	$	82,671
Municipal securities		2,035		—		—			2,035
Total securities available-for-sale	$	84,972	$	4	$	(270	)	$	84,706

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
	June 30, 2016		December 31, 2015
	(In thousands)
Less than one year	$	68,122	$	37,694
Due in 1 - 5 years		78,208		47,012
Total	$	146,330	$	84,706

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 June 30, 2016 and December 31, 2015

	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 June 30, 2016
Corporate debt	$	23,507	$	(39	)	$	—	$	—	$	23,507	$	(39	)
As of December 31, 2015
Corporate debt	$	70,651	$	(270	)	$	—	$	—	$	70,651	$	(270	)