Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Summary of available-for-sale securities

The following is a summary of available-for-sale securities at December 31:

($ in thousands)		2021				2020
Marketable Securities:	Fair Value Hierarchy	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Certificates of deposit
with unrecognized losses for less than 12 months		$	401	$	400	$	—	$	—
with unrecognized gains		—		—		—		—
Total Certificates of deposit	Level 1	401		400		—		—
U.S. Treasury and agency notes
with unrecognized losses for less than 12 months		1,360		1,358		—		—
with unrecognized gains		—		—		801		803
Total U.S. Treasury and agency notes	Level 2	1,360		1,358		801		803
Corporate notes
with unrecognized losses for less than 12 months		9,231		9,225		708		707
with unrecognized gains		—		—		1,257		1,261
Total Corporate notes	Level 2	9,231		9,225		1,965		1,968
		$	10,992	$	10,983	$	2,766	$	2,771

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

The following tables summarize the maturities, at par, of marketable securities by year ($ in thousands):

December 31, 2021	2022		2023		Total
Certificates of deposit	$	400	$	—	$	400
U.S. Treasury and agency notes	$	855	500		$	1,355
Corporate notes	8,925		250		9,175
	$	10,180	$	750	$	10,930

December 31, 2020	2021		Total
U.S. Treasury and agency notes	801		801
Corporate notes	1,950		1,950
	$	2,751	$	2,751