3.INVESTMENTS

The following table summarizes the Company’s investments at:

December 31, 2016	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value			Continuous Unrealized Loss Position less than 12 Months		Continuous Unrealized Loss Position greater than 12 Months
Available-for-sale
Short-term:
Commercial paper	$	40,382	$	-	$	-	$		40,382	$	-	$	-
Municipal securities	140,379		-		181		140,198			181		-
U.S. government agency securities	26,057		-		6		26,051			6		-
Variable rate demand notes	13,923		-		-		13,923			-		-
Long-term:
Municipal securities	2,403		-		9		2,394			9		-

Total	$	223,144	$	-	$	196	$		222,948	$	196	$	-


December 31, 2015	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value			Continuous Unrealized Loss Position less than 12 Months		Continuous Unrealized Loss Position greater than 12 Months

Held-to-Maturity
Short-term:
Commercial paper	$	3,978	$	-	$	-	$		3,978	$	-	$	-
Municipal securities	709,207		63		192		709,078			192		-
U.S. government agency securities	23,369		-		58		23,311			58		-
U.S. Treasuries	8,056		-		13		8,043			13		-
Long-term:
Municipal securities	11,071		-		8		11,063			8		-
U.S. government agency securities	4,277		-		25		4,252			25		-

Total	$	759,958	$	63	$	296	$	759,725		$	296	$	-

During the years ended December 31, 2016 and 2015, realized gains or losses recognized on the sale of investments were not significant. During June 2016, the Company sold a large portion of its held-to-maturity investments prior to maturity in order to fund a portion of a common stock repurchase (see Note 13). As a result, the Company’s remaining held-to-maturity investments of $43.7 million were transferred to available-for-sale effective June 15, 2016.

The Company’s investments at December 31, 2016 and 2015 in commercial paper, municipal securities, U.S. government agency securities, U.S. treasuries and/or variable rate demand notes (“VRDNs”) carried investment grade credit ratings. VRDNs are floating rate municipal bonds with embedded put options that allow the bondholder to sell the security at par plus accrued interest. All of the put options are secured by a pledged liquidity source. While they are classified as marketable investment securities, the put option allows the VRDNs to be liquidated at par on a same day, or more generally, on a seven day settlement basis.

The following table summarizes the underlying contractual maturities of the Company’s investments at:

	December 31, 2016				December 31, 2015

	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Less than 1 year:
Commercial paper	$	40,382	$	40,382	$	3,978	$	3,978
Municipal securities	140,379		140,198		709,207		709,078
U.S. government agency securities	26,057		26,051		23,369		23,311
U.S. Treasuries	-		-		8,056		8,043
Due 1 -10 years:
Municipal securities	2,403		2,394		11,071		11,063
U.S. government agency securities	-		-		4,277		4,252
Variable rate demand notes	3,917		3,917		-		-
Due 11 - 20 years:
Variable rate demand notes	6,003		6,003		-		-
Due 21 - 30 years:
Variable rate demand notes	4,003		4,003		-		-

Total	$	223,144	$	222,948	$	759,958	$	759,725

The Company recognized a net gain through earnings on its trading securities as follows for the years ended:

	2016		2015		2014
Gain (loss) on transfer from available-for-sale to trading	$	-	$	-	$	-
Gain on trading securities sold	-		250		978
(Loss) gain on trading securities held	-		-		(177)

Gain on trading securites	$	-	$	250	$	801