Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2013

Investments, Debt and Equity Securities [Abstract]

Summary of available-for-sale securities

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

		June 30, 2013				December 31, 2012
($ in thousands)	Fair Value Hierarchy	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Certificates of deposit
with unrecognized losses for less than 12 months		$	1,623	$	1,615	$	1,578	$	1,571
with unrecognized losses for more than 12 months		354		353		508		507
with unrecognized gains		6,633		6,667		5,586		5,628
Total Certificates of deposit	Level 1	8,610		8,635		7,672		7,706
US Treasury and agency notes
with unrecognized losses for less than 12 months		3,913		3,894		3,057		3,024
with unrecognized losses for more than 12 months		5,312		5,288		874		873
with unrecognized gains		7,195		7,244		12,175		12,267
Total US Treasury and agency notes	Level 2	16,420		16,426		16,106		16,164
Corporate notes
with unrecognized losses for less than 12 months		9,479		9,305		1,993		1,971
with unrecognized losses for more than 12 months		329		328		201		200
with unrecognized gains		20,423		20,668		29,210		29,653
Total Corporate notes	Level 2	30,231		30,301		31,404		31,824
Municipal notes
with unrecognized losses for less than 12 months		2,185		2,160		1,961		1,948
with unrecognized losses for more than 12 months		720		716		620		613
with unrecognized gains		6,618		6,678		6,702		6,794
Total Municipal notes	Level 2	9,523		9,554		9,283		9,355
		$	64,784	$	64,916	$	64,465	$	65,049

Summary of maturities, at par, of marketable securities

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

(in thousands)
At June 30, 2013	2013		2014		2015		2016		2017		Total
Certificates of deposit	$	1,255	$	1,627	$	4,213	$	1,301	$	97	$	8,493
U.S. Treasury and agency notes	3,566		7,287		3,448		1,750		391		16,442
Corporate notes	2,988		6,729		10,017		5,650		3,574		28,958
Municipal notes	1,335		4,365		2,205		1,135		205		9,245
	$	9,144	$	20,008	$	19,883	$	9,836	$	4,267	$	63,138

(in thousands)
At December 31, 2012	2013		2014		2015		2016		Total
Certificates of deposit	$	1,268	$	1,627	$	4,316	$	301	$	7,512
U.S. Treasury and agency notes	6,285		7,248		2,633		11		16,177
Corporate notes	10,916		6,729		9,420		3,325		30,390
Municipal notes	2,305		4,340		1,960		400		9,005
	$	20,774	$	19,944	$	18,329	$	4,037	$	63,084