Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Summary of available-for-sale securities

The following is a summary of available-for-sale securities at:

($ in thousands)		March 31, 2020				December 31, 2019
Marketable Securities:	Fair Value Hierarchy	Cost		Fair Value		Cost		Fair Value
Certificates of deposit
with unrealized losses for less than 12 months		$	251	$	250	$	251	$	250
with unrealized losses for more than 12 months		—		—		—		—
with unrealized gains		1,799		1,812		1,799		1,806
Total Certificates of deposit	Level 1	2,050		2,062		2,050		2,056
U.S. Treasury and agency notes
with unrealized losses for less than 12 months		—		—		6,485		6,479
with unrealized losses for more than 12 months		—		—		—		—
with unrealized gains		18,252		18,365		14,413		14,434
Total U.S. Treasury and agency notes	Level 2	18,252		18,365		20,898		20,913
Corporate notes
with unrealized losses for less than 12 months		10,455		10,441		1,004		1,002
with unrealized losses for more than 12 months		—		—		—		—
with unrealized gains		1,350		1,353		13,082		13,106
Total Corporate notes	Level 2	11,805		11,794		14,086		14,108
Municipal notes
with unrealized losses for less than 12 months		—		—		—		—
with unrealized losses for more than 12 months		—		—		—		—
with unrealized gains		2,001		2,007		1,999		2,007
Total Municipal notes	Level 2	2,001		2,007		1,999		2,007
		$	34,108	$	34,228	$	39,033	$	39,084

Summary of maturities, at par, of marketable securities by year

The following tables summarize the maturities, at par, of marketable securities as of:

	March 31, 2020
($ in thousands)	2020		2021		Total
Certificates of deposit	$	2,049	$	—	$	2,049
U.S. Treasury and agency notes	17,439		802		18,241
Corporate notes	11,400		400		11,800
Municipal notes	2,000		—		2,000
	$	32,888	$	1,202	$	34,090

	December 31, 2019
($ in thousands)	2020		2021		Total
Certificates of deposit	$	2,049	$	—	$	2,049
U.S. Treasury and agency notes	20,393		502		20,895
Corporate notes	13,685		400		14,085
Municipal notes	2,000		—		2,000
	$	38,127	$	902	$	39,029