Marketable Securities

12 Months Ended

Dec. 31, 2011

Marketable Securities [Abstract]

Marketable Securities

6.   Marketable Securities

Marketable securities at December 31, 2011 and 2010 consisted of debt securities, as detailed below, and equity securities.  The aggregate fair value of the equity securities was $3.0 million and $3.6 million at December 31, 2011 and 2010, respectively, and the aggregate cost basis was $4.0 million at both December 31, 2011 and 2010.  The Company also held restricted marketable securities at both December 31, 2011 and December 31, 2010, which consisted of debt securities, as detailed below, that collateralize letters of credit and lease obligations.

The following tables summarize the amortized cost basis of debt securities included in marketable securities, the aggregate fair value of those securities, and gross unrealized gains and losses on those securities at December 31, 2011 and 2010.  The Company classifies its debt securities, other than mortgage-backed securities, based on their contractual maturity dates.  Maturities of mortgage-backed securities have been estimated based primarily on repayment characteristics and experience of the senior tranches that the Company holds.

	Amortized	Fair	Unrealized
At December 31, 2011	Cost Basis	Value	Gains	(Losses)	Net
Unrestricted
Maturities within one year
U.S. government obligations	$12,025	$12,067	$42		$42
U.S. government guaranteed corporate bonds	15,263	15,316	53		53
U.S. government guaranteed collateralized mortgage obligations	623	622		(1)	(1)
Municipal bonds	15,314	15,326	13	(1)	12
	43,225	43,331	108	(2)	106
Maturities after one year through five years
U.S. government obligations	272,433	272,752	400	(81)	319
Mortgage-backed securities	104	28	___	(76)	(76)
	272,537	272,780	400	(157)	243
Maturities after five years through ten years
Mortgage-backed securities	164	87	___	(77)	(77)
	315,926	316,198	508	(236)	272
Restricted
Maturities within one year
U.S. government obligations	3,347	3,357	10		10
Maturities after one year through five years
U.S. government obligations	2,572	2,583	11	___	11
	5,919	5,940	21	___	21
	$321,845	$322,138	$529	$(236)	$293

	Amortized	Fair	Unrealized
At December 31, 2010	Cost Basis	Value	Gains	(Losses)	Net
Unrestricted
Maturities within one year
U.S. government obligations	$83,635	$83,684	$54	$(5)	$49
U.S. government guaranteed corporate bonds	48,173	48,531	358		358
U.S. government guaranteed      collateralized mortgage obligations	2,027	2,131	104		104
Municipal bonds	1,597	1,603	6		6
Mortgage-backed securities	875	847	___	(28)	(28)
	136,307	136,796	522	(33)	489
Maturities after one year through five years
U.S. government obligations	352,345	350,683	64	(1,726)	(1,662)
U.S. government guaranteed corporate bonds	15,522	15,477		(45)	(45)
Mortgage-backed securities	110	38	___	(72)	(72)
	367,977	366,198	64	(1,843)	(1,779)
Maturities after five years through ten years
Mortgage-backed securities	284	243	___	(41)	(41)
	504,568	503,237	586	(1.917)	(1,331)
Restricted
Maturities within one year
U.S. government obligations	2,922	2,921		(1)	(1)
Maturities after one year through five years
U.S. government obligations	4,135	4,118	___	(17)	(17)
	7,057	7,039	___	(18)	(18)
	$511,625	$510,276	$586	$(1,935)	$(1,349)

At December 31, 2011 and 2010, marketable securities included an additional unrealized loss of $1.0 million and $0.4 million, respectively, related to one equity security in the Company’s marketable securities portfolio.

The following table shows the fair value of the Company’s marketable securities that have unrealized losses and that are deemed to be only temporarily impaired, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position, at December 31, 2011 and 2010.  The debt securities listed at December 31, 2011, excluding mortgage-backed securities, mature at various dates through December 2014.  The mortgage-backed securities listed at December 31, 2011 mature at various dates through April 2018.

	Less than 12 Months		12 Months or Greater		Total
At December 31, 2011	Fair Value	Unrealized Loss	Fair Value	Unrealized Loss	Fair Value	Unrealized Loss
Unrestricted
U.S. government obligations	$103,529	$(81)			$103,529	$(81)
U.S. government guaranteed   collateralized mortgage   obligations	623	(1)			623	(1)
Municipal bonds	4,603	(1)			4,603	(1)
Equity security	3,019	(1,025)			3,019	(1,025)
Mortgage-backed securities	_____	____	$116	$(152)	116	(152)
	$111,774	$(1,108)	$116	$(152)	$111,890	$(1,260)
At December 31, 2010
Unrestricted
U.S. government obligations	$340,444	$(1,731)			$340,444	$(1,731)
U.S. government guaranteed   corporate bonds	19,005	(45)			19,005	(45)
Equity security	3,612	(433)			3,612	(433)
Mortgage-backed securities	_____	____	$1,128	$(141)	1,128	(141)
	363,061	(2,209)	1,128	(141)	364,189	(2,350)
Restricted
U.S. government obligations	6,154	(18)	____	____	6,154	(18)
	6,154	(18)	____	____	6,154	(18)
	$369,215	$(2,227)	$1,128	$(141)	$370,343	$(2,368)

Realized gains and losses are included as a component of investment income.  For the years ended December 31, 2011, 2010, and 2009, total realized gains and losses on sales of marketable securities were not material.  In computing realized gains and losses, the Company computes the cost of its investments on a specific identification basis.  Such cost includes the direct costs to acquire the security, adjusted for the amortization of any discount or premium.

The Company’s assets that are measured at fair value on a recurring basis, at December 31, 2011 and 2010, were as follows:

		Fair Value Measurements at Reporting Date Using
	Fair Value	Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Other Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
At December 31, 2011
Unrestricted
Available-for-sale marketable securities
U.S. government obligations	$284,819		$284,819
U.S. government guaranteed corporate bonds	15,316		15,316
U.S. government guaranteed collateralized mortgage obligations	622		622
Municipal bonds	15,326		15,326
Mortgage-backed securities	115		115
Equity security	3,019	$3,019	_______
	319,217	3,019	316,198

Restricted
Available-for-sale marketable securities
U.S. government obligations	5,940	_____	5,940
	$325,157	$3,019	$322,138
At December 31, 2010
Unrestricted
Available-for-sale marketable securities
U.S. government obligations	$434,367		$434,367
U.S. government guaranteed corporate bonds	64,008		64,008
U.S. government guaranteed collateralized mortgage obligations	2,131		2,131
Municipal bonds	1,603		1,603
Mortgage-backed securities	1,128		1,128
Equity security	3,612	$3,612	_______
	506,849	3,612	503,237
Restricted
Available-for-sale marketable securities
U.S. government obligations	7,039	_____	7,039
	$513,888	$3,612	$510,276

Marketable securities included in Level 2 were valued using a market approach utilizing prices and other relevant information, such as interest rates, yield curves, prepayment speeds, loss severities, credit risks, and default rates, generated by market transactions involving identical or comparable assets.  The Company considers market liquidity in determining the fair value for these securities.  During the year ended December 31, 2010, deterioration in the credit quality of a marketable security subjected the Company to the risk of not being able to recover the carrying value of these securities.  As a result, the Company recognized a $0.1 million impairment charge related to its Level 2 marketable securities in 2010, which the Company considered to be other-than-temporarily impaired.  The Company did not record any charges for other-than-temporary impairment of its Level 2 marketable securities in 2011 and 2009.

The Company held one Level 3 marketable security, which had a fair value of $0 at December 31, 2011 and 2010.  This Level 3 security was valued using information provided by the Company’s investment advisors and other sources, including quoted bid prices which took into consideration the securities’ lack of liquidity.  In 2009, the Company recorded a charge of $0.1 million for other-than-temporary impairment of this Level 3 marketable security; therefore, as of December 31, 2009, the fair value of this security had been written down to zero.  There were no purchases, sales, or maturities of Level 3 marketable securities and no unrealized gains or losses related to Level 3 marketable securities for the years ended December 31, 2011 and 2010.  There were no transfers of marketable securities between Levels 1, 2, or 3 classifications during the years ended December 31, 2011 and 2010.