Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2015

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)		June 30, 2015				December 31, 2014
Marketable Securities:	Fair Value Hierarchy	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Certificates of deposit
with unrecognized losses for less than 12 months		$	3,925	$	3,899	$	2,522	$	2,492
with unrecognized losses for more than 12 months		620		619		837		832
with unrecognized gains		3,789		3,798		5,379		5,395
Total Certificates of deposit	Level 1	8,334		8,316		8,738		8,719
US Treasury and agency notes
with unrecognized losses for less than 12 months		723		720		1,919		1,910
with unrecognized losses for more than 12 months		200		200		702		700
with unrecognized gains		1,764		1,790		1,182		1,207
Total US Treasury and agency notes	Level 2	2,687		2,710		3,803		3,817
Corporate notes
with unrecognized losses for less than 12 months		8,049		7,996		3,872		3,841
with unrecognized losses for more than 12 months		2,520		2,507		4,423		4,405
with unrecognized gains		12,893		12,934		16,897		16,963
Total Corporate notes	Level 2	23,462		23,437		25,192		25,209
Municipal notes
with unrecognized losses for less than 12 months		1,532		1,518		739		733
with unrecognized losses for more than 12 months		641		634		457		456
with unrecognized gains		2,662		2,674		3,183		3,206
Total Municipal notes	Level 2	4,835		4,826		4,379		4,395
		$	39,318	$	39,289	$	42,112	$	42,140

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):

At June 30, 2015	2015		2016		2017		2018		2019		Total
Certificates of deposit	$	1,355	$	2,492	$	631	$	3,800	$	—	$	8,278
U.S. Treasury and agency notes	419		100		959		1,079		188		2,745
Corporate notes	3,653		6,604		6,625		5,845		—		22,727
Municipal notes	1,080		1,325		940		1,355		—		4,700
	$	6,507	$	10,521	$	9,155	$	12,079	$	188	$	38,450

At December 31, 2014	2015		2016		2017		2018		Total
Certificates of deposit	$	4,213	$	1,501	$	831	2,149		$	8,694
U.S. Treasury and agency notes	1,176		600		1,209		879		3,864
Corporate notes	9,588		6,704		6,498		1,625		24,415
Municipal notes	2,105		1,235		790		125		4,255
	$	17,082	$	10,040	$	9,328	$	4,778	$	41,228