6. CASH AND CASH EQUIVALENTS AND INVESTMENTS

Cash and cash equivalents and investments from our continuing operations consist of the following as of December 31, 2011 and 2010:


	December 31, 2011
			(Dollars in thousands) Gross Unrealized
	Cost		Gain		(Loss)			Fair Value
Cash and cash equivalents:
Cash	$	157,317	$	—	$	—		$	157,317
Money market funds		122,827		448		—			123,275

Total cash and cash equivalents		280,144		448		—			280,592

Short-term investments (available-for-sale):
U.S. Treasury bills		133,648		31		(5	)		133,674
U.S. Government Agencies		26,962		—		(29	)		26,933

Total short-term investments (available-for-sale)		160,610		31		(34	)		160,607

Total cash and cash equivalents and short-term investments	$	440,754	$	479	$	(34	)	$	441,199

Long-term investments (available-for-sale):
Municipal bonds	$	11,150	$	—	$	(735	)	$	10,415


	December 31, 2010
			(Dollars in thousands) Gross Unrealized
	Cost		Gain		(Loss)			Fair Value
Cash and cash equivalents:
Cash	$	147,412	$	—	$	—		$	147,412
Money market funds		112,936		296		—			113,232

Total cash and cash equivalents		260,348		296		—			260,644

Short-term investments (available-for-sale):
U.S. Treasury bills		159,672		7		(8	)		159,671

Total short-term investments (available-for-sale)		159,672		7		(8	)		159,671

Total cash and cash equivalents and short-term investments	$	420,020	$	303	$	(8	)	$	420,315

Long-term investments (available-for-sale):
Municipal bonds	$	11,750	$	—	$	(439	)	$	11,311

In the table above, unrealized holding losses as of December 31, 2011 relate to cash equivalents and short-term investments that have been in a continuous unrealized loss position for less than one year. The table also includes unrealized holding losses that relate to our long-term investments in municipal bonds, which are ARS. When evaluating our investments for possible impairment, we review factors such as the length of time and extent to which fair value has been less than the cost basis, the financial condition of the investee, and our ability and intent to hold the investment for a period of time that may be sufficient for anticipated recovery in fair value. The decline in the fair value of our municipal bonds through December 31, 2011 is attributable to the continued lack of activity in the ARS market, exposing these investments to liquidity risk.

Included in cash and cash equivalents above are amounts related to certain of our European campuses that are operated on a not-for-profit basis. The cash and cash equivalents related to these schools have restrictions which require that the funds be utilized for these particular not-for-profit schools. The amount of cash and cash equivalents of our not-for-profit schools with restrictions was $74.5 million and $58.5 million at December 31, 2011 and 2010, respectively. Restrictions on cash balances have not affected our ability to fund operations.

Money market funds. Money market funds are mutual funds that invest in lower risk securities and generate low yields. Such funds maintain clear investment guidelines and seek to limit credit, market and liquidity risks.

Municipal bonds: Municipal bonds represent debt obligations issued by states, cities, counties, and other governmental entities, which earn federally tax-exempt interest. ARS generally have stated terms to maturity of greater than one year. We classify investments in ARS as non-current on our consolidated balance sheets within other assets. Auctions can "fail" when the number of sellers of the security exceeds the buyers for that particular auction period. In the event that an auction fails, the interest rate resets at a rate based on a formula determined by the individual security. The ARS for which auctions have failed continue to accrue interest and are auctioned on a set interval until the auction succeeds, the issuer calls the securities, or they mature. As of December 31, 2011, we have determined these investments are at risk for impairment due to the nature of the liquidity of the market over the past year. Cumulative unrealized losses as of December 31, 2011, amount to $0.7 million and are reflected within other comprehensive loss as a component of stockholders' equity. We believe this impairment is temporary, as we do not intend to sell the investments and it is unlikely we will be required to sell the investments before recovery of their amortized cost basis.

U.S. Treasury bills: Debt obligations issued by the U.S. government that pay interest at maturity. U.S. Treasury bills are generally traded at discounts to par value and mature in one year or less.

U.S. Government Agencies: Debt obligations issued by a Government Sponsored Enterprise ("GSE") which pay interest. GSE's are privately-held corporations with public purposes created by the U.S. Congress to reduce the cost of capital for certain borrowing sectors of the economy. Our debt obligations are issued by Federal Home Loan Banks and generally traded at discounts to par value. These obligations mature in one year or less and have the implicit backing of the U.S. Government although they are not direct obligations of the U.S. Government.

A schedule of available-for-sale investments segregated by their original stated terms to maturity as of December 31, 2011 and 2010, are as follows:


	Less than one year		One to five years		Five to ten years		Greater than ten years		Total
	(Dollars in thousands)
Original stated term to maturity of available-for-sale-investments as of December 31, 2011	$	160,607	$	—	$	—	$	10,415	$	171,022
Original stated term to maturity of available-for-sale-investments as of December 31, 2010	$	159,671	$	—	$	—	$	11,311	$	170,982

Realized gains or losses resulting from sales of investments during the years ended December 31, 2011, 2010 and 2009 were not significant.

Fair Value Measurements

The fair value measure of accounting for financial instruments establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.

As of December 31, 2011, we held investments that are required to be measured at fair value on a recurring basis. These investments (available-for-sale) consist of U.S. Treasury bills and U.S. Government Agencies that are publicly traded and for which market prices are readily available.

As of December 31, 2011, we also held investments in ARS, which are classified as available-for-sale and reflected at fair value. The auction events for these investments have been failing for over two years. The fair values of these securities are estimated utilizing a discounted cash flow analysis as of December 31, 2011. These analyses consider, among other items, the collateralization underlying the security investments, the creditworthiness of the counterparty, the timing of expected future cash flows, and the expectation of the next time the security is expected to have a successful auction. These securities were also compared, when possible, to other observable market data with similar characteristics.

Investments measured at fair value on a recurring basis subject to the disclosure requirements issued by the FASB ASC under Topic 820—Fair Value Measurements at December 31, 2011 and 2010, were as follows:


	As of December 31, 2011
	(Dollars in thousands)
	Level 1		Level 2		Level 3		Total
Municipal bonds	$	—	$	—	$	10,415	$	10,415
U.S. Treasury bills		133,674		—		—		133,674
U.S. Government Agencies		26,933		—		—		26,933

Totals	$	160,607	$	—	$	10,415	$	171,022

	As of December 31, 2010
	(Dollars in thousands)
	Level 1		Level 2		Level 3		Total
Municipal bonds	$	—	$	—	$	11,311	$	11,311
U.S. Treasury bills		159,671		—		—		159,671

Totals	$	159,671	$	—	$	11,311	$	170,982

The following table presents a rollforward of our assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as defined in FASB ASC Topic 820 for the year ended December 31, 2011:


	(Dollars in thousands)
Balance at December 31, 2010	$	11,311
Unrealized loss		(296	)
Settlements		(600	)

Balance at December 31, 2011	$	10,415