Marketable Securities (Tables)

9 Months Ended

Sep. 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)		September 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		$	2,826	$	2,814	$	2,522	$	2,492
with unrecognized losses for more than 12 months		250		250		837		832
with unrecognized gains		5,003		5,013		5,379		5,395
Total Certificates of deposit	Level 1	8,079		8,077		8,738		8,719
US Treasury and agency notes
with unrecognized losses for less than 12 months		131		131		1,919		1,910
with unrecognized losses for more than 12 months		—		—		702		700
with unrecognized gains		1,660		1,669		1,182		1,207
Total US Treasury and agency notes	Level 2	1,791		1,800		3,803		3,817
Corporate notes
with unrecognized losses for less than 12 months		10,719		10,657		3,872		3,841
with unrecognized losses for more than 12 months		2,094		2,081		4,423		4,405
with unrecognized gains		7,348		7,369		16,897		16,963
Total Corporate notes	Level 2	20,161		20,107		25,192		25,209
Municipal notes
with unrecognized losses for less than 12 months		1,241		1,232		739		733
with unrecognized losses for more than 12 months		405		401		457		456
with unrecognized gains		2,079		2,089		3,183		3,206
Total Municipal notes	Level 2	3,725		3,722		4,379		4,395
		$	33,756	$	33,706	$	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 September 30, 2015	2015		2016		2017		2018		2019		Total
Certificates of deposit	$	395	$	2,492	$	631	$	4,510	$	—	$	8,028
U.S. Treasury and agency notes	—		100		959		579		193		1,831
Corporate notes	305		4,572		6,525		6,270		1,795		19,467
Municipal notes	200		1,025		940		1,455		—		3,620
	$	900	$	8,189	$	9,055	$	12,814	$	1,988	$	32,946

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