5.INVESTMENTS

The following table summarizes the Company’s investments at:

June 30, 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	$	182,130	$	-	$	-	$	182,130	$	-	$	-
U.S. Treasuries	74,981		6		-		74,987		-		-
Certificates of deposit	32,001		-		-		32,001		-		-
Municipal securities	587,740		82		42		587,780		42		-
U.S. government agency securities	350,859		27		10		350,876		10		-
Long-term:
Municipal securities	52,364		33		5		52,392		5		-
U.S. government agency securities	-		-		-		-		-		-
Available-for-sale
Variable rate demand notes	3,901		-		-		3,901		-		-

Total	$	1,283,976	$	148	$	57	1,284,067		$	57	$	-

Trading
Short-term:
Auction rate securities							3,246
Long-term:
Auction rate securities							-

Total							$	1,287,313


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 agency securities	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- and six-months ended June 30, 2015 and 2014, realized gains or losses recognized on the sale of investments were not significant. During the three- and six-months ended June 30, 2015 and 2014, the net gains recognized on the Company’s trading securities were not significant.

The Company’s investments at June 30, 2015 and December 31, 2014 in commercial paper, U.S. Treasuries, certificates of deposit, 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 June 30, 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:

	June 30, 2015				December 31, 2014

	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Less than 1 year:
Commercial paper	$	182,130	$	182,130	$	19,482	$	19,480
U.S. Treasuries	74,981		74,987		-		-
Certificates of deposit	32,001		32,001		-		-
Municipal securities	587,740		587,780		744,542		744,647
U.S. government agency securities	350,859		350,876		9,199		9,198
Due 1 - 10 years:
Municipal securities	52,364		52,392		42,940		42,950
Due 11 - 20 years:
Auction rate securities	3,246		3,246		3,910		3,910
Due 21 - 30 years:
Variable rate demand notes	3,901		3,901		4,001		4,001

Total	$	1,287,222	$	1,287,313	$	824,074	$	824,186