Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2016

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, 2016				December 31, 2015
Marketable Securities:	Fair Value Hierarchy	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Certificates of deposit
with unrecognized losses for less than 12 months		$	465	$	464	$	4,810	$	4,797
with unrecognized losses for more than 12 months		—		—		239		238
with unrecognized gains		6,481		6,510		2,800		2,805
Total Certificates of deposit	Level 1	6,946		6,974		7,849		7,840
US Treasury and agency notes
with unrecognized losses for less than 12 months		—		—		860		857
with unrecognized losses for more than 12 months		—		—		—		—
with unrecognized gains		2,028		2,037		736		738
Total US Treasury and agency notes	Level 2	2,028		2,037		1,596		1,595
Corporate notes
with unrecognized losses for less than 12 months		5,084		5,056		14,638		14,516
with unrecognized losses for more than 12 months		3,160		3,139		2,080		2,061
with unrecognized gains		11,949		11,981		3,334		3,339
Total Corporate notes	Level 2	20,193		20,176		20,052		19,916
Municipal notes
with unrecognized losses for less than 12 months		666		661		1,742		1,725
with unrecognized losses for more than 12 months		330		329		301		298
with unrecognized gains		2,528		2,542		1,435		1,441
Total Municipal notes	Level 2	3,524		3,532		3,478		3,464
		$	32,691	$	32,719	$	32,975	$	32,815

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, 2016
($ in thousands)	2016		2017		2018		2019		Total
Certificates of deposit	$	1,594	$	631	$	4,510	$	169	$	6,904
U.S. Treasury and agency notes	100		1,234		579		143		2,056
Corporate notes	4,159		6,525		6,669		2,301		19,654
Municipal notes	975		940		1,455		75		3,445
	$	6,828	$	9,330	$	13,213	$	2,688	$	32,059

	December 31, 2015
($ in thousands)	2016		2017		2018		2019		Total
Certificates of deposit	$	2,492	$	631	$	4,510	169		$	7,802
U.S. Treasury and agency notes	100		759		579		188		1,626
Corporate notes	4,572		6,525		6,462		1,881		19,440
Municipal notes	995		940		1,455		—		3,390
	$	8,159	$	8,855	$	13,006	$	2,238	$	32,258