Short-term Investments (Tables)

9 Months Ended

Sep. 30, 2018

Investments Debt And Equity Securities [Abstract]

Summary of Short-term Investments

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