3. Cash and Cash Equivalents and Short-Term Investments

The following are summaries of cash, cash equivalents and short-term investments (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
As of December 31, 2011:
Cash and money market funds	$	3,908	$	—	$	—		$	3,908
Government sponsored enterprise debt securities		23,900		2		(1	)		23,901
U.S. Treasury securities		6,500		—		—			6,500

	$	34,308	$	2	$	(1	)	$	34,309

Reported as:
Cash and cash equivalents								$	9,148
Short-term investments									25,161

								$	34,309

As of December 31, 2010:
Cash and money market funds	$	6,705	$	—	$	—		$	6,705
Commercial paper		2,000		—		—			2,000
U.S. Treasury securities		38,127		1		(3	)		38,125

	$	46,832	$	1	$	(3	)	$	46,830

Reported as:
Cash and cash equivalents								$	8,705
Short-term investments									38,125

								$	46,830

At December 31, 2011 and 2010, the contractual maturities of investments held were one year or less. The Company sold $7.1 million of its investments prior to the maturity date in the twelve months ended December 31, 2011 and recorded an immaterial gain on the sale. The Company did not sell any of its investments prior to maturity during 2010. The Company's short-term restricted cash of $0.2 million at December 31, 2011 is related to its obligation under the sublease for its corporate headquarters which is secured by a certificate of deposit. The Company's long-term restricted cash of $0.3 million at December 31, 2011 is related to its corporate credit card program.