4.INVESTMENTS

The following table summarizes the Company’s investments at:

March 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	$	15,991	$	-	$	1	$	15,990	$	-	$	-
Municipal securities	622,082		48		-		622,130		-		-
U.S. Government Agencies	1,401		-		-		1,401		-		-
Long-term:
Municipal securities	33,662		8		-		33,670		-		-
U.S. Government Agencies	7,578		-		7		7,571		-		-
Available-for-sale
Variable rate demand notes	3,900		-		-		3,900		-		-
Total	$	684,614	$	56	$	8	684,662		$	-	$	-
Trading
Short-term:
Auction rate securities							3,910
Long-term:
Auction rate securities							-
Total							$	688,572

December 31, 2014	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	$	19,482	$	-	$	2	$	19,480	$	-	$	-
Municipal securities	744,542		105		-		744,647		-		-
U.S. Government Agencies	9,199		-		1		9,198		-		-
Long-term:
Municipal securities	42,940		10		-		42,950		-		-
Available-for-sale
Variable rate demand notes	4,001		-		-		4,001		-		-
Total	$	820,164	$	115	$	3	820,276		$	-	$	-
Trading
Short-term:
Auction rate securities							3,910
Long-term:
Auction rate securities							-
Total							$	824,186

During the three-months ended March 31, 2015 and 2014, realized gains or losses recognized on the sale of investments were not significant. During the three-months ended March 31, 2015 and 2014, the net gains recognized on the Company’s trading securities was not significant.

The Company’s investments at March 31, 2015 and December 31, 2014 in commercial paper, municipal securities, U.S. government agency securities 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. All of the Company’s investments at March 31, 2015 and December 31, 2014 in municipal, educational or other public body securities with an auction reset feature (“auction rate securities”) also carried investment grade credit ratings.

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

	March 31, 2015				December 31, 2014

	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Less than 1 year:
Commercial paper	$	15,991	$	15,990	$	19,482	$	19,480
Municipal securities	622,082		622,130		744,542		744,647
U.S. government agency securities	1,401		1,401		9,199		9,198
Due 1 - 10 years:
Municipal securities	33,662		33,670		42,940		42,950
U.S. government agency securities	7,578		7,571
Due 11 - 20 years:
Auction rate securities	3,910		3,910		3,910		3,910
Due 21 - 30 years:
Variable rate demand notes	3,900		3,900		4,001		4,001
Total	$	688,524	$	688,572	$	824,074	$	824,186