Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2016

Fair Value Disclosures [Abstract]

Schedule of Assets Measured at Fair Value on a Recurring Basis

The following table presents our assets and liabilities measured at fair value on a recurring basis using the above input categories (in thousands):

	As of March 31, 2016								As of December 31, 2015
Description	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Cash equivalents:
Money market funds	$	21,330	$	—	$	—	$	21,330	$	210,533	$	—	$	—	$	210,533
Total cash equivalents	21,330		—		—		21,330		210,533		—		—		210,533
Short-term investments:
Certificates of deposit	—		17,254		—		17,254		—		19,124		—		19,124
Corporate notes and bonds	—		443,250		—		443,250		—		447,267		—		447,267
U.S. Government agencies	—		285,523		—		285,523		—		301,384		—		301,384
Total short-term investments	—		746,027		—		746,027		—		767,775		—		767,775
Total assets measured at fair value	$	21,330	$	746,027	$	—	$	767,357	$	210,533	$	767,775	$	—	$	978,308
Liabilities
Contingent earn-out	$	—	$	—	$	35,588	$	35,588	$	—	$	—	$	—	$	—
Total liabilities measured at fair value	$	—	$	—	$	35,588	$	35,588	$	—	$	—	$	—	$	—