Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2017

The following is a summary of available-for-sale securities at December 31:



($ in thousands)		2017				2016
Marketable Securities:	Fair Value Hierarchy	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Certificates of deposit
with unrecognized losses for less than 12 months		$	6,238	$	6,222	$	1,868	$	1,863
with unrecognized losses for more than 12 months		102		100		—		—
with unrecognized gains		2,088		2,089		3,320		3,329
Total Certificates of deposit	Level 1	8,428		8,411		5,188		5,192
U.S. Treasury and agency notes
with unrecognized losses for less than 12 months		29,741		29,669		947		946
with unrecognized losses for more than 12 months		137		135		—		—
with unrecognized gains		152		153		857		859
Total U.S. Treasury and agency notes	Level 2	30,030		29,957		1,804		1,805
Corporate notes
with unrecognized losses for less than 12 months		18,230		18,159		11,658		11,592
with unrecognized losses for more than 12 months		2,804		2,788		1,053		1,042
with unrecognized gains		—		—		3,431		3,435
Total Corporate notes	Level 2	21,034		20,947		16,142		16,069
Municipal notes
with unrecognized losses for less than 12 months		10,298		10,288		2,556		2,526
with unrecognized losses for more than 12 months		999		987		271		269
with unrecognized gains		277		278		812		814
Total Municipal notes	Level 2	11,574		11,553		3,639		3,609

		$	71,066	$	70,868	$	26,773	$	26,675

The following tables summarize the maturities, at par, of marketable securities by year ($ in thousands):