Investments

The cost and carrying value of available-for-sale investments were as follows (in thousands):



September 30, 2017	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Carrying Value
Debt securities: corporate bonds and U.S. Treasuries	$	70,850	$	42	$	(12	)	$	70,880
Marketable equity securities	59,716		671		(7		)	60,380
Total	$	130,566	$	713	$	(19	)	$	131,260



December 31, 2016	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Carrying Value
Debt securities: corporate bonds	$	4,306	$	82	$	(6	)	$	4,382
Marketable equity securities	10,400		10,327		(38		)	20,689
Total	$	14,706	$	10,409	$	(44	)	$	25,071

The amortized cost and carrying value of investments in debt securities, by contractual maturity, are shown below. Actual maturity dates may differ from contractual maturity dates because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties (in thousands):



	September 30, 2017				December 31, 2016
	Amortized Cost		Carrying Value		Amortized Cost		Carrying Value
Due in one year or less	$	70,228	$	70,260	$	182	$	183
Due after one year through five years	622		620		4,124		4,199
Total	$	70,850	$	70,880	$	4,306	$	4,382

Debt Securities

The Company owns U.S. Treasury Bills and certain corporate bonds which were purchased based on the maturity and yield-to-maturity of the bond and an analysis of the fundamental characteristics of the issuer. At September 30, 2017 and December 31, 2016, there were no material unrealized losses on such securities. There were no impairment losses recorded on debt securities during the three or nine months ended September 30, 2017 and 2016.

Marketable Equity Securities

The Company’s investment in marketable equity securities at September 30, 2017 principally consisted of common stock of Century and, to a lesser extent, other publicly traded small-capitalization companies in the U.S. and select foreign markets. At September 30, 2017, the Company reviewed its equity securities in an unrealized loss position and concluded the investment in Century was other than temporarily impaired based on the actual price the Company received on the sale of the securities subsequent to September 30, 2017. The other securities in an unrealized loss position were not other-than-temporarily impaired as the declines were not of sufficient duration and severity, and publicly-available financial information, collectively, did not indicate impairment. The primary cause of the losses on those securities was normal market volatility. No other material impairment losses were recorded during the three or nine months ended September 30, 2017 and 2016.