Short-term Investments

9 Months Ended

Sep. 30, 2018

Investments Debt And Equity Securities [Abstract]

Short-term Investments

Note 3. Short-term Investments

The Company’s short-term investments consist of short-term bank deposits and marketable securities. As of September 30, 2018 and December 31, 2017 total short-term investments were $2.5 million and $23.6 million, respectively. The balance of investments as of December 31, 2017 included bank deposits of $15.0 million with maturities of more than three months but less than one year, and were short-term deposits stated at cost and approximated market value. As of December 31, 2017, the Company's short-term bank depositsbore interest at a weighted average annual interest rate of1.6%.  As of September 30, 2018, all short-term bank deposits were liquidated.

The following is a summary of short-term investments at September 30, 2018:

	September 30, 2018
(Dollars in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
Corporate debt securities		2,495		4		—		2,499
Total	$	2,495	$	4	$	—	$	2,499

The following is a summary of short-term investments (net of bank deposits) at December 31, 2017:

	December 31, 2017
(Dollars in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Certificates of deposit	$	1,462	$	—	$	—		$	1,462
Corporate debt securities		7,149		—		(3	)		7,146
Total	$	8,611	$	—	$	(3	)	$	8,608

All short-term investments are held as available-for-sale and mature within twelve months of September 30, 2018 and December 31, 2017. Management reviews unrealized losses individually and in the aggregate at each reporting period and has determined that none of the balances are other than temporarily impaired based upon the brief duration of time that the investments have been at a loss position as of September 30, 2018 and December 31, 2017.