Fair Value Measurements (Tables)

9 Months Ended

Sep. 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 September 30, 2016
Money market funds	$	37,609	$	—	$	—	$	37,609
Securities available-for-sale
Corporate debt		—		94,781		—		94,781
Trading securities
Corporate debt		—		74,546		—		74,546
Mutual funds held in rabbi trust		—		1,328		—		1,328
Foreign currency forward position		—		318		—		318
Total	$	37,609	$	170,973	$	—	$	208,582
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
	September 30, 2016		December 31, 2015
	(In thousands)
Notional value	$	59,962	$	45,716
Fair value of notional		59,644		45,362
Fair value of the asset	$	318	$	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 September 30, 2016
Securities available-for-sale
Corporate debt	$	94,760	$	59	$	(38	)	$	94,781
Total securities available-for-sale		94,760		59		(38	)		94,781
Trading securities
Corporate debt		74,370		188		(12	)		74,546
Mutual funds held in rabbi trust		1,167		161		—			1,328
Total trading securities		75,537		349		(12	)		75,874
Total investments	$	170,297	$	408		(50	)	$	170,655
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
	September 30, 2016		December 31, 2015
	(In thousands)
Less than one year	$	99,264	$	37,694
Due in 1 - 5 years		71,391		47,012
Total	$	170,655	$	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 September 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 September 30, 2016
Corporate debt	$	49,177	$	(41	)	$	2,000	$	(9	)	$	51,177	$	(50	)
As of December 31, 2015
Corporate debt	$	70,651	$	(270	)	$	—	$	—		$	70,651	$	(270	)