Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2014

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, 2014				December 31, 2013
Marketable Securities:	Fair Value Hierarchy	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Certificates of deposit
with unrecognized losses for less than 12 months		$	1,362	$	1,345	$	1,690	$	1,677
with unrecognized losses for more than 12 months		359		355		110		110
with unrecognized gains		6,645		6,681		6,298		6,334
Total Certificates of deposit	Level 1	8,366		8,381		8,098		8,121
US Treasury and agency notes
with unrecognized losses for less than 12 months		3,289		3,281		4,672		4,664
with unrecognized losses for more than 12 months		1,702		1,699		1,699		1,694
with unrecognized gains		4,581		4,621		3,713		3,760
Total US Treasury and agency notes	Level 2	9,572		9,601		10,084		10,118
Corporate notes
with unrecognized losses for less than 12 months		4,105		4,076		7,270		7,192
with unrecognized losses for more than 12 months		1,796		1,787		530		523
with unrecognized gains		21,926		22,123		21,945		22,173
Total Corporate notes	Level 2	27,827		27,986		29,745		29,888
Municipal notes
with unrecognized losses for less than 12 months		524		520		1,688		1,677
with unrecognized losses for more than 12 months		249		247		318		316
with unrecognized gains		6,133		6,184		5,267		5,316
Total Municipal notes	Level 2	6,906		6,951		7,273		7,309
		$	52,671	$	52,919	$	55,200	$	55,436

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 March 31, 2014	2014		2015		2016		2017		2018		Total
Certificates of deposit	$	1,437	$	4,213	$	1,501	$	731	$	409	$	8,291
U.S. Treasury and agency notes	4,575		3,336		600		1,092		—		$	9,603
Corporate notes	3,769		9,937		6,704		6,098		247		$	26,755
Municipal notes	2,785		2,205		1,235		495		—		$	6,720
	$	12,566	$	19,691	$	10,040	$	8,416	$	656	$	51,369

At December 31, 2013	2014		2015		2016		2017		Total
Certificates of deposit	$	1,627	$	4,213	$	1,501	$	681	$	8,022
U.S. Treasury and agency notes	5,485		3,336		600		692		$	10,113
Corporate notes	6,729		10,037		6,704		5,174		$	28,644
Municipal notes	3,325		2,205		1,235		295		$	7,060
	$	17,166	$	19,791	$	10,040	$	6,842	$	53,839