(7)	Investments

Investments include investment-grade bonds and U.S. Treasury obligations having maturities of up to five years (the "bond portfolio"). Investments in the bond portfolio are reported as available-for-sale and are carried at fair value. Investments maturing less than one year from the balance sheet date are included in short-term investments and investments maturing more than one year from the balance sheet date are included in other assets in the consolidated balance sheets. Management performs an analysis of the nature of the unrealized losses on available-for-sale investments to determine whether such losses are other-than-temporary. Unrealized losses, representing the excess of the purchase price of an investment over its fair value as of the end of a period, considered to be other-than-temporary are to be included as a charge in the statement of income while unrealized losses considered to be temporary are to be included as a component of shareholders' equity. Investments whose values are based on quoted market prices in active markets are classified within Level 1. Investments that trade in markets that are not considered to be active, but are valued based on quoted market prices, are classified within Level 2. As Level 2 investments include positions that are not traded in active markets, valuations may be adjusted to reflect illiquidity and/or non-transferability, which are generally based on available market information. Transfers between levels are recognized as of the beginning of the period. Fair value of the bond portfolio was determined using Level 1 inputs related to U.S. Treasury obligations and money market investments and Level 2 inputs related to investment-grade corporate bonds, mortgage-backed securities and direct obligations of government agencies. Unrealized gains, net of unrealized losses, on the investments in the bond portfolio were $1,068,000 and $786,000 at March 31, 2012 and December 31, 2011, respectively.

The amortized cost and fair market values of available-for-sale investments are as follows at March 31, 2012 and December 31, 2011 (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
March 31, 2012

Money market investments	$	551	$	—	$	—	$	551
Mortgage-backed securities		2,934		109		—		3,043
Corporate bonds and direct obligations of government agencies		68,368		1,018		97		69,289
U.S. Treasury obligations		12,996		41		3		13,034


Total	$	84,849	$	1,168	$	100	$	85,917


December 31, 2011

Money market investments	$	1,989	$	—	$	—	$	1,989
Mortgage-backed securities		3,017		61		18		3,060
Corporate bonds and direct obligations of government agencies		51,014		819		126		51,707
U.S. Treasury obligations		11,682		51		1		11,732


Total	$	67,702	$	931	$	145	$	68,488

For those available-for-sale investments with unrealized losses at March 31, 2012 and December 31, 2011, the following table summarizes the duration of the unrealized loss (in thousands):


	Less than 12 months				12 months or longer				Total
	Fair Market Value		Unrealized Loss		Fair Market Value		Unrealized Loss		Fair Market Value		Unrealized Loss
March 31, 2012

Corporate bonds and direct obligations of government agencies	$	14,956	$	97	$	—	$	—	$	14,956	$	97
U.S. Treasury obligations		11,286		3		—		—		11,286		3


Total	$	26,242	$	100	$	—	$	—	$	26,242	$	100


December 31, 2011

Mortgage-backed securities	$	468	$	18	$	—	$	—	$	468	$	18
Corporate bonds and direct obligations of government agencies		6,067		126		—		—		6,067		126
U.S. Treasury obligations		591		1		—		—		591		1


Total	$	7,126	$	145	$	—	$	—	$	7,126	$	145