Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2018

Investments All Other Investments [Abstract]

Cash Equivalents, Restricted Cash and Short-Term Investments Classified as Available-for-sale Securities

Cash equivalents, restricted cash and short-term investments which are classified as available-for-sale securities, consisted of the following (in thousands):

March 31, 2018	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Money market funds (cash equivalents)	$	126,526	$	—	$	—		$	126,526
U.S. government agency securities		16,972		—		(4	)		16,968
Restricted cash (money market funds)		175		—		—			175
Total financial assets	$	143,673	$	—	$	(4	)	$	143,669
Classified as:
Cash and cash equivalents								$	126,526
Short-term investments									16,968
Restricted cash (money market funds)									175
								$	143,669

December 31, 2017	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Money market funds (cash equivalents)	$	14,334	$	—	$	—		$	14,334
U.S. government agency securities		16,474		—		(3	)		16,471
Restricted cash (money market funds)		5,330		3		—			5,333
Agency securities		1,500		—		—			1,500
Total financial assets	$	37,638	$	3	$	(3	)	$	37,638
Classified as:
Cash and cash equivalents								$	14,334
Short-term investments									17,971
Restricted cash (money market funds)									5,333
								$	37,638

- Definition

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

+ References + Details