Short- and Long-Term Investments and Investments on Deposit for Licensure

12 Months Ended

Dec. 31, 2011

Short- and Long-Term Investments and Investments on Deposit for Licensure [Abstract]

Short- and Long-Term Investments and Investments on Deposit for Licensure

(4) Short- and Long-Term Investments and Investments on Deposit for Licensure

The amortized cost, gross unrealized holding gains, gross unrealized holding losses and fair value for available-for-sale short- and long-term investments and investments on deposit for licensure held at December 31, 2011 were as follows:

	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value
Auction rate securities	$	12,550	$	—	$	999	$	11,551
Certificates of deposit		118,081		13		—		118,094
Commercial paper		172,657		2		95		172,564
Corporate bonds		565,382		2,852		1,510		566,724
Debt securities of government sponsored entities		289,901		742		100		290,543
Equity index funds		40,146		1,355		658		40,843
Money market funds		15,067		—		—		15,067
Municipal bonds		382,049		16,978		1		399,026
U.S. Treasury securities		26,045		80		1		26,124
Total	$	1,621,878	$	22,022	$	3,364	$	1,640,536

The amortized cost, gross unrealized holding gains, gross unrealized holding losses and fair value for available-for-sale short- and long-term investments and investments on deposit for licensure held at December 31, 2010 were as follows:

	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value
Auction rate securities	$	22,650	$	—	$	1,357	$	21,293
Certificates of deposit		13,651		—		—		13,651
Commercial paper		14,797		—		4		14,793
Corporate bonds		235,775		2,327		186		237,916
Debt securities of government sponsored entities		331,893		623		465		332,051
Federally insured corporate bonds		21,097		360		3		21,454
Money market funds		20,315		—		—		20,315
Municipal bonds		301,234		1,145		1,562		300,817
U.S. Treasury securities		21,592		130		1		21,721
Total	$	983,004	$	4,585	$	3,578	$	984,011

The amortized cost and fair value of investments in debt securities, by contractual maturity, for available-for-sale short- and long-term investments and investments on deposit for licensure held at December 31, 2011 were as follows:

	Amortized Cost		Fair Value
Maturing within one year	$	551,658	$	552,129
Maturing between one year and five years		739,375		741,922
Maturing between five years and ten years		192,856		205,905
Maturing in greater than ten years		97,845		99,737
Total	$	1,581,734	$	1,599,693

Investments in equity index funds with a cost of $40,146 and a fair value of $40,843 are excluded from the table above because they do not have contractual maturities.

For the years ended December 31, 2011 and 2010, a net unrealized gain of $17,651 and a net unrealized loss of $1,201, respectively, was recorded to accumulated other comprehensive income as a result of changes in fair value for investments classified as available-for-sale.

The following tables show the fair value of the Company’s available-for-sale investments with unrealized losses that are not deemed to be other-than-temporarily impaired at December 31, 2011 and 2010. Investments are aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position:

	Less than 12 Months						12 Months or Greater
	Fair Value		Gross Unrealized Holding Losses		Total Number of Securities		Fair Value		Gross Unrealized Holding Losses		Total Number of Securities
2011:
Auction rate securities	$	—	$	—		—	$	11,551	$	999		3
Commercial paper		149,074		95		12		—		—		—
Corporate bonds		185,231		1,498		98		8,989		12		1
Debt securities of government sponsored entities		103,766		100		28		—		—		—
Equity index funds		17,021		658		5		—		—		—
Municipal bond		5,129		1		1		—		—		—
U.S. Treasury securities		12,025		1		3		—		—		—
Total temporarily impaired securities	$	472,246	$	2,353		147	$	20,540	$	1,011		4
	Less than 12 Months						12 Months or Greater
	Fair Value		Gross Unrealized Holding Losses		Total Number of Securities		Fair Value		Gross Unrealized Holding Losses		Total Number of Securities
2010:
Auction rate securities	$	—	$	—		—	$	21,293	$	1,357		6
Commercial paper		19,495		4		8		—		—		—
Corporate bonds		71,278		186		37		—		—		—
Debt securities of government sponsored entities		86,881		465		29		—		—		—
Federally insured corporate bond		4,036		3		1		—		—		—
Municipal bonds		160,860		1,562		64		—		—		—
U.S. Treasury securities		9,564		1		3		—		—		—
Total temporarily impaired securities	$	352,114	$	2,221		142	$	21,293	$	1,357		6

The Company typically invests in highly-rated debt securities and its investment policy generally limits the amount of credit exposure to any one issuer. Additionally, the Company’s portfolio includes a relatively small position in equity index funds whose underlying assets are issued by companies in the Standard and Poor’s 500 or by similar quality issuers. The Company’s investment policy requires investments to generally be investment grade, primarily rated single-A or better, with the objective of minimizing the potential risk of principal loss and maintaining appropriate liquidity for the Company’s operations. Fair values were determined for each individual security in the investment portfolio. When evaluating investments for other-than-temporary impairment, the Company reviews factors such as the length of time and extent to which fair value has been below cost basis, the financial condition of the issuer, general market conditions and the Company’s intent to sell, or whether it is more likely than not that the Company will be required to sell the investment before recovery of a security’s amortized cost basis. During the year ended December 31, 2011, the Company did not record any charges for other-than-temporary impairment of its available-for-sale securities.

As of December 31, 2011, the Company’s investments in debt securities in an unrealized loss position all hold investment grade ratings by various credit rating agencies. Additionally, the issuers have been current on all interest payments. The temporary declines in value at December 31, 2011 are primarily due to fluctuations in short-term market interest rates and the lack of liquidity of auction rate securities. Auction rate securities that have been in an unrealized loss position for greater than 12 months have experienced losses due to the lack of liquidity for these instruments, not as a result of impairment of the underlying debt securities. The unrealized loss positions on equity index funds as of December 31, 2011 are primarily due to recent market volatility in the corresponding equity indices that these funds are designed to replicate. These equity index funds have been trading below cost continuously for less than six months with the maximum decline of any equity holding below cost position of six percent which the Company believes is typical of the market volatility of these types of funds at any point in time but not representative of other-than-temporary impairment. Additionally, each equity index fund in an unrealized loss position at December 31, 2011 is actively traded and all received a dividend payment in the fourth quarter of 2011. The Company does not intend to sell the debt and equity securities in an unrealized loss position prior to maturity or recovery and it is not likely that the Company will be required to sell these securities prior to maturity or recovery; therefore, there is no indication of other-than-temporary impairment for these securities.