FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2016

FAIR VALUE MEASUREMENTS

Schedule of fair value measurements along with the level within the fair value hierarchy in which the fair value measurements fall

The following table presents the Company’s fair value measurements as of March 31, 2016 along with the level within the fair value hierarchy in which the fair value measurements in their entirety fall. Amounts in the table are in thousands.

			Fair Value Measurement at March 31, 2016 Using:
			Quoted Prices		Significant
			in Active		Other		Significant
			Markets for		Observable		Unobservable
	Fair Value at		Identical Assets		Inputs		Inputs
Description	March 31, 2016		(Level 1)		(Level 2)		(Level 3)
Cash and cash equivalents
Cash and money market	$	38,151	$	38,151	$	—	$	—
Certificates of deposit		14,000		—		14,000		—
Available-for-Sale
Marketable securities
Corporate bonds		132,906		—		132,906		—
Asset backed securities		62,348		—		62,348		—
U.S. government agency securities		7,065		—		7,065		—
Certificates of deposit		5,502		—		5,502		—
Commercial paper		2,620		—		2,620		—
Total	$	262,592	$	38,151	$	224,441	$	—

The following table presents the Company’s fair value measurements as of December 31, 2015 along with the level within the fair value hierarchy in which the fair value measurements in their entirety fall. Amounts in the table are in thousands.

			Fair Value Measurement at December 31, 2015 Using:
			Quoted Prices		Significant
			in Active		Other		Significant
			Markets for		Observable		Unobservable
	Fair Value at		Identical Assets		Inputs		Inputs
Description	December 31, 2015		(Level 1)		(Level 2)		(Level 3)
Cash and cash equivalents
Cash and money market	$	37,435	$	37,435	$	—	$	—
Commercial Paper		3,700		—		3,700		—
Available-for-Sale
Marketable securities
Corporate bonds		179,211		—		179,211		—
Asset backed securities		77,495		—		77,495		—
U.S. government agency securities		7,039		—		7,039		—
Certificates of deposit		1,999		—		1,999		—
Total	$	306,879	$	37,435	$	269,444	$	—

Schedule of gross unrealized losses and fair values of investments in an unrealized loss position

		March 31, 2016
		Less than 12 months			12 months or greater				Total
(In thousands)		Fair Value		Gross Unrealized Loss		Fair Value		Gross Unrealized Loss		Fair Value		Gross Unrealized Loss
Marketable Securities
Asset backed securities	$	43,177	$	(44)	$	—	$	—	$	43,177	$	(44)
Corporate bonds		41,402		(41)		—		—		41,402		(41)
Commercial Paper		2,620		(1)		—		—		2,620		(1)
U.S. government agency securities		2,499		—		—		—		2,499		—
Total	$	89,698	$	(86)	$	—	$	—	$	89,698	$	(86)

Summary of contractual maturities available for the sale of investments in debt securities

The following summarizes contractual underlying maturities of the Company’s available-for-sale investments in debt securities at March 31, 2016 (in thousands):

		Due one year or less			Due after one year through four years
Description		Cost		Fair Value		Cost		Fair Value
Marketable Securities
Corporate bonds	$	98,989	$	99,012	$	33,865	$	33,894
Certificates of deposit		5,500		5,502		—		—
Commercial Paper		2,621		2,620		—		—
U.S. government agency securities		2,500		2,500		4,557		4,565
Asset backed securities		1		1		62,379		62,347
Total	$	109,611	$	109,635	$	100,801	$	100,806