As of December 31, 2012, and December 31, 2011, unrealized gains and losses on available-for-sale securities are summarized as follows (in thousands):



December 31, 2012	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash, Cash Equivalents and Available-for-Sale Securities
Obligations of U.S. government agencies	$	9,013	$	1	$	(1	)	$	9,013
Obligations of U.S. corporations	6,953		—		(1		)	6,952
Obligations of Non-U.S. corporations	3,336		—		—			3,336
Money market funds	905		—		—			905
Cash	58,039		—		—			58,039
	$	78,246	$	1	$	(2	)	$	78,245
Amounts included in cash and cash equivalents	$	58,944	$	—	$	—		$	58,944
Amounts included in short-term investments	19,302		1		(2		)	19,301
	$	78,246	$	1	$	(2	)	$	78,245



December 31, 2011	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash, Cash Equivalents and Available-for-Sale Securities
Obligations of U.S. government agencies	$	6,219	$	1	$	(1	)	$	6,219
Obligations of U.S. corporations	2,633		—		(3		)	2,630
Obligations of Non-U.S. corporations	1,048		—		—			1,048
Agency bonds	275		—		—			275
Money market funds	10,035		—		—			10,035
Cash	65,016		—		—			65,016
	$	85,226	$	1	$	(4	)	$	85,223
Amounts included in cash and cash equivalents	$	75,326	$	—	$	—		$	75,326
Amounts included in short-term investments	9,900		1		(4		)	9,897
	$	85,226	$	1	$	(4	)	$	85,223