Financial Instruments

12 Months Ended

Dec. 31, 2018

Investments All Other Investments [Abstract]

5.	Financial Instruments

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

-December 31, 2018	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Money market funds (cash equivalents)	$	29,090	$	—	$	—		$	29,090
Agency securities (cash equivalents)		999		—	$	—			999
Restricted cash		50		—		—			50
U.S. government agency securities		74,144		1		(6	)		74,139
Agency securities		14,774		1		—			14,775
Total financial assets	$	119,057	$	2	$	(6	)	$	119,053
Classified as:
Cash and cash equivalents								$	30,089
Short-term investments									88,914
Restricted cash									50
								$	119,053

December 31, 2017	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Money market funds	$	14,334	$	—	$	—		$	14,334
U.S. government agency securities		16,473		—		(2	)		16,471
Restricted cash		5,330		3		—			5,333
Agency securities		1,500		—		—			1,500
Total financial assets	$	37,637	$	3	$	(2	)	$	37,638
Classified as:
Cash and cash equivalents								$	14,334
Short-term investments									17,971
Restricted cash									5,333
								$	37,638

As of December 31, 2018, the remaining contractual maturities of available-for-sale securities was less than one year. There have been no material realized gains or losses on available-for-sale securities for the periods presented. The carrying amounts of cash, other assets, other receivables, accounts payable and other payables approximate their fair values due to the short-term maturity of these instruments.