Short term and Long term Investments and Restricted Deposits

Short term and long term investments and restricted deposits by investment type consist of the following:



	December 31, 2013									December 31, 2012
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	246,085	$	245	$	(7,494	)	$	238,836	$	110,941	$	581	$	(221	)	$	111,301
Corporate securities	293,912		2,782		(608		)	296,086		290,691		4,615		(195		)	295,111
Restricted certificates of deposit	5,891		—		—			5,891		5,890		—		—			5,890
Restricted cash equivalents	26,642		—		—			26,642		14,455		—		—			14,455
Municipal securities:
General obligation	54,003		555		(136		)	54,422		85,440		1,157		(26		)	86,571
Pre-refunded	10,835		82		—			10,917		5,337		85		—			5,422
Revenue	68,801		545		(292		)	69,054		82,781		1,313		(30		)	84,064
Variable rate demand notes	28,575		—		—			28,575		23,385		—		—			23,385
Asset backed securities	138,803		579		(332		)	139,050		73,570		1,082		(15		)	74,637
Mortgage backed securities	33,974		—		(83		)	33,891		—		—		—			—
Cost and equity method investments	22,239		—		—			22,239		11,298		—		—			11,298
Life insurance contracts	15,369		—		—			15,369		15,023		—		—			15,023
Total	$	945,129	$	4,788	$	(8,945	)	$	940,972	$	718,811	$	8,833	$	(487	)	$	727,157

The Company’s investments are classified as available-for-sale with the exception of life insurance contracts and certain cost and equity method investments. The Company’s investment policies are designed to provide liquidity, preserve capital and maximize total return on invested assets with the focus on high credit quality securities. The Company limits the size of investment in any single issuer other than U.S. treasury securities and obligations of U.S. government corporations and agencies. The Company's mortgage backed securities are issued by the Federal National Mortgage Association and carry guarantees by the U.S. government. As of December 31, 2013, 52% of the Company’s investments in securities recorded at fair value that carry a rating by S&P or Moody’s were rated AAA/Aaa, 68% were rated AA-/Aa3 or higher, and 94% were rated A-/A3 or higher. At December 31, 2013, the Company held certificates of deposit, life insurance contracts and cost and equity method investments which did not carry a credit rating.

The fair value of available-for-sale investments with gross unrealized losses by investment type and length of time that individual securities have been in a continuous unrealized loss position were as follows:



	December 31, 2013										December 31, 2012
	Less Than 12 Months					12 Months or More					Less Than 12 Months					12 Months or More
	Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	(6,188	)	$	172,365	$	(1,307	)	$	26,454	$	(219	)	$	56,033	$	(2	)	$	201
Corporate securities	(400		)	52,725		(207		)	5,020		(195		)	44,208		—			—
Municipal securities:
General obligation	(72		)	3,480		(63		)	2,426		(26		)	7,930		—			—
Revenue	(292		)	27,789		—			—		(30		)	3,090		—			—
Asset backed securities	(333		)	37,689		—			—		(15		)	8,192		—			—
Mortgage backed securities	(83		)	33,891		—			—		—			—		—			—
Total	$	(7,368	)	$	327,939	$	(1,577	)	$	33,900	$	(485	)	$	119,453	$	(2	)	$	201

As of December 31, 2013, the gross unrealized losses were generated from 83 positions out of a total of 343 positions. The decline in fair value of fixed income securities is a result of movement in interest rates subsequent to the purchase of the security.

For each security in an unrealized loss position, the Company assesses whether it intends to sell the security or if it is more likely than not the Company will be required to sell the security before recovery of the amortized cost basis for reasons such as liquidity, contractual or regulatory purposes. If the security meets this criterion, the decline in fair value is other-than-temporary and is recorded in earnings. The Company does not intend to sell these securities prior to maturity and it is not likely that the Company will be required to sell these securities prior to maturity; therefore, there is no indication of other than temporary impairment for these securities.

The contractual maturities of short term and long term investments and restricted deposits are as follows:



	December 31, 2013								December 31, 2012
	Investments				Restricted Deposits				Investments				Restricted Deposits
	Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value
One year or less	$	101,537	$	102,126	$	40,633	$	40,637	$	136,997	$	138,101	$	33,897	$	33,928
One year through five years	609,755		610,589		6,301		6,309		429,053		435,728		358		358
Five years through ten years	157,003		151,221		—		—		93,907		93,778		—		—
Greater than ten years	29,900		30,090		—		—		24,599		25,264		—		—
Total	$	898,195	$	894,026	$	46,934	$	46,946	$	684,556	$	692,871	$	34,255	$	34,286

Actual maturities may differ from contractual maturities due to call or prepayment options. Asset backed and mortgage backed securities are included in the one year through five years category, while cost and equity method investments and life insurance contracts are included in the five years through ten years category. The Company has an option to redeem at amortized cost substantially all of the securities included in the greater than ten years category listed above.

The Company continuously monitors investments for other-than-temporary impairment. Certain investments have experienced a decline in fair value due to changes in credit quality, market interest rates and/or general economic conditions. The Company recognizes an impairment loss for cost and equity method investments when evidence demonstrates that it is other-than-temporarily impaired. Evidence of a loss in value that is other than temporary may include the absence of an ability to recover the carrying amount of the investment or the inability of the investee to sustain a level of earnings that would justify the carrying amount of the investment.