INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2011

INVESTMENTS

Summary of investments in held-to-maturity, available-for-sale and trading securities

December 31, 2011	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:
U.S. Treasuries	$	8,034	$	5	$	-	$	8,039	$	-	$	-
Certificates of deposit		29,034		1		-	29,035		-		-
Corporate bonds		2,022		-		-	2,022		-		-
Municipal securities		284,605		-		64	284,541		64		-
U.S. government agency securities		16,005		2		-	16,007		-		-
Available-for-sale
Short-term:
Variable rate demand notes		58,924		-		-	58,924		-		-
Long-term:
Auction rate securities		3,320		-		-	3,320		-		-
Total	$	401,944	$	8	$	64	401,888		$	64	$	-
Trading
Short-term:
Auction rate securities							12,658
Long-term:
Auction rate securities							19,874
Total							$	434,420

December 31, 2010	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:
U.S. Treasuries	$	66,521	$	-	$	2	$	66,519	$	2	$	-
Certificates of deposit	7,004		-		-		7,004		-		-
Municipal securities	71,266		-		15		71,251		15		-
U.S. government agency securities	19,688		-		8		19,680		8		-
Available-for-sale
Short-term:
Variable rate demand notes	56,107		-		-		56,107		-		-
Long-term:
Auction rate securities	27,790		-		2,408		25,382		-		2,408
Total	$	248,376	$	-	$	2,433	245,943		$	25	$	2,408
Trading
Short-term:
Auction rate securities							24,063
Long-term:
Auction rate securities							18,807
Total							$	288,813

Summarizes the underlying contractual maturities of the Company's investments

	December 31, 2011				December 31, 2010
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Less than 1 year:
U.S. Treasuries	$	8,034	$	8,039	$	66,521	$	66,519
Certificates of deposit	29,034		29,035		7,004		7,004
Corporate bonds	2,022		2,022		-		-
Municipal securities	284,605		284,541		71,266		71,251
U.S. government agency securities	16,005		16,007		19,688		19,680
Due 1 - 10 years:
Variable rate demand notes	5,775		5,775		3,001		3,001
Due 11 - 20 years:
Variable rate demand notes	12,716		12,716		11,002		11,002
Auction rate securities	5,158		5,158		10,305		9,819
Due 21 - 30 years:
Variable rate demand notes	27,902		27,902		30,426		30,426
Auction rate securities	25,134		25,134		48,779		46,857
Due 31 - 40 years:
Variable rate demand notes	12,532		12,532		11,678		11,678
Auction rate securities	5,559		5,559		11,576		11,576
Total	$	434,476	$	434,420	$	291,246	$	288,813