INVESTMENTS

The Company considers all of its investments as available-for-sale securities. Realized gains and losses on the sale of investments are determined on a specific identification basis.

The amortized cost, gross unrealized gain or loss and estimated fair value of short-term and long-term investments by security type were as follows as of June 30, 2012 and December 31, 2011 (in thousands):



	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
As of June 30, 2012
State and municipal bonds	$	1,073,585	$	68,231	$	(506	)	$	1,141,310
U.S. Treasury securities	79,706		1,184		(11		)	80,879
Government-sponsored enterprise securities ⁽¹⁾	23,417		1,115		—			24,532
Residential mortgage-backed securities ⁽²⁾	335,891		15,113		(123		)	350,881
Commercial mortgage-backed securities	12,772		1,163		—			13,935
Asset-backed securities ⁽³⁾	9,566		373		—			9,939
Corporate debt and other securities	1,050,565		23,230		(1,942		)	1,071,853
	$	2,585,502	$	110,409	$	(2,582	)	$	2,693,329
Equity method investments ⁽⁴⁾								19,582
								$	2,712,911

	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
As of December 31, 2011
State and municipal bonds	$	970,746	$	62,215	$	(7	)	$	1,032,954
U.S. Treasury securities	88,934		2,410		(4		)	91,340
Government-sponsored enterprise securities⁽¹⁾	140,595		2,694		(11		)	143,278
Residential mortgage-backed securities ⁽²⁾	354,713		14,097		(12		)	368,798
Commercial mortgage-backed securities	13,801		1,024		—			14,825
Asset-backed securities⁽³⁾	12,840		664		—			13,504
Corporate debt and other securities	1,051,874		23,804		(10,178		)	1,065,500
	$	2,633,503	$	106,908	$	(10,212	)	$	2,730,199
Equity method investments⁽⁴⁾								21,315
								$	2,751,514


⁽¹⁾	Includes FDIC-insured Temporary Liquidity Guarantee Program (“TLGP”) securities as of December 31, 2011. As of June 30, 2012, the Company no longer held any TLGP securities.


⁽²⁾	Agency pass-through, with the timely payment of principal and interest guaranteed.


⁽³⁾	Includes auto loans, credit card debt, and rate reduction bonds.


⁽⁴⁾	Includes investments in entities accounted for under the equity method of accounting and therefore are presented at their carrying value.

The amortized cost and estimated fair value of available-for-sale debt securities by contractual maturity were as follows as of June 30, 2012 and December 31, 2011 (in thousands):



	As of June 30, 2012				As of December 31, 2011
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Maturities:
Within 1 year	$	354,206	$	355,756	$	315,362	$	317,067
1 to 5 years	761,127		783,621		984,503		1,006,221
5 to 10 years	589,954		631,276		536,577		574,207
Over 10 years	880,215		922,676		797,061		832,704
Total	$	2,585,502	$	2,693,329	$	2,633,503	$	2,730,199

Investments with long-term option adjusted maturities, such as residential and commercial mortgage-backed securities, are included in the “Over 10 years” category. Actual maturities may differ due to call or prepayment rights.

Gross investment gains of $10.8 million and gross investment losses of $0.1 million were realized on sales of investments for the quarter ended June 30, 2012. This compares to gross investment gains of $4.1 million and no gross investment losses realized on sales of investments for the quarter ended June 30, 2011. Gross investment gains of $15.1 million and gross investment losses of $0.1 million were realized on sales of investments for the six months ended June 30, 2012. This compares to gross investment gains of $5.8 million and gross investment losses of $0.1 million realized on sales of investments for the six months ended June 30, 2011. All realized gains and losses are recorded in other income, net in the Company’s consolidated statements of operations and comprehensive income.

The following table shows the Company’s investments’ gross unrealized losses and fair value at June 30, 2012 and December 31, 2011, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands):



At June 30, 2012	Less than 12 months					12 months or more					Total
Description of Securities	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
State and municipal bonds	$	46,826	$	(506	)	$	—	$	—		$	46,826	$	(506	)
U.S. Treasury securities	18,635		(11		)	—		—			18,635		(11		)
Government-sponsored enterprise securities	—		—			—		—			—		—
Residential mortgage-backed securities	11,606		(122		)	52		(1		)	11,658		(123		)
Commercial mortgage-backed securities	—		—			—		—			—		—
Asset-backed securities	—		—			—		—			—		—
Corporate debt and other securities	86,740		(599		)	101,017		(1,343		)	187,757		(1,942		)
Total	$	163,807	$	(1,238	)	$	101,069	$	(1,344	)	$	264,876	$	(2,582	)

At December 31, 2011	Less than 12 months					12 months or more					Total
Description of Securities	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
State and municipal bonds	$	9,436	$	(7	)	$	—	$	—		$	9,436	$	(7	)
U.S. Treasury securities	4,932		(4		)	—		—			4,932		(4		)
Government-sponsored enterprise securities	12,495		(11		)	—		—			12,495		(11		)
Residential mortgage-backed securities	5,127		(11		)	43		(1		)	5,170		(12		)
Commercial mortgage-backed securities	—		—			—		—			—		—
Asset-backed securities	—		—			—		—			—		—
Corporate debt and other securities	350,294		(10,178		)	—		—			350,294		(10,178		)
Total	$	382,284	$	(10,211	)	$	43	$	(1	)	$	382,327	$	(10,212	)

The unrealized losses presented in this table do not meet the criteria for treatment as an other-than-temporary impairment. The unrealized losses are the result of, among other factors, interest rate movements. The Company has not decided to sell, and it is not more-likely-than-not that the Company will be required to sell before a recovery of the amortized cost basis of these securities.

The Company continues to review its investment portfolios under its impairment review policy. Given the current market conditions and the significant judgments involved, there is a continuing risk that declines in fair value may occur and that other-than-temporary impairments may be recorded in future periods.