4. INVESTMENTS

Below is a summary of the amortized cost and estimated market values of the Company’s marketable securities as of December 31, 2017, and 2016. The estimated market values provided are Level 2 valuations as defined by ASC 820.


	2017				2016
	Amortized Cost		Market Value		Amortized Cost		Market Value
	(Dollars in thousands)
Municipal bonds:
Current	$	5,970	$	5,977	$	4,601	$	4,610
Due from one through five years		10,260		10,536		12,133		12,486
Due from six through ten years		5,005		5,197		7,705		7,804
Due from eleven through twenty years		2,404		2,539		1,223		1,222
Total	$	23,639	$	24,249	$	25,662	$	26,122

The unrealized gains and losses on marketable securities at December 31, 2017 and 2016 were as follows:


	2017					2016
	Unrealized Gains		Unrealized Losses			Unrealized Gains		Unrealized Losses
	(Dollars in thousands)
Municipal bonds	$	634	$	(24	)	$	546	$	(86	)

At each reporting date, the Company reviews its investments to determine whether a decline in fair value below the amortized cost basis is other-than-temporary. To determine whether a decline in value is other-than-temporary, the Company considers all available evidence, including the issuer’s financial condition, the severity and duration of the decline in fair value, and the Company’s intent and ability to hold the investment for a reasonable period of time sufficient for any forecasted recovery. If a decline in value is deemed other-than-temporary, the Company records a reduction in the carrying value to the estimated fair value. The Company determined that no other-than-temporary impairment exists for the years ended December 31, 2017, 2016, and 2015.