INVESTMENT SECURITIES

6 Months Ended

Jun. 30, 2018

Investments, Debt and Equity Securities [Abstract]

INVESTMENT SECURITIES

Our investments as of June 30, 2018 and December 31, 2017 are classified as held-to-maturity. Held-to-maturity investments are recorded at amortized cost.

The following tables summarize our investment securities at June 30, 2018 and December 31, 2017:

(in thousands)	June 30, 2018
	Amortized cost, as adjusted		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
Short-term investments:
Obligations of domestic governmental agencies (maturing between July 2018 and April 2019) (held-to-maturity)	$	20,573	$	--	$	17	$	20,556
Total short-term investment securities	$	20,573	$	--	$	17	$	20,556

	December 31, 2017
	Amortized cost, as adjusted		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
Short-term investments:
Obligations of domestic governmental agencies (maturing between January 2018 and November 2018) (held-to-maturity)	$	27,999		--	$	35	$	27,964
Total short-term investment securities	$	27,999		--	$	35	$	27,964