Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value of Financial Instruments

Schedule of estimated fair values of financial instruments outstanding

The estimated fair values of financial instruments outstanding at December 31, 2012 and 2011 were as follows (in thousands):

	2012
	Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash and cash equivalents	$	2,529	$	—	$	—		$	2,529
Short-term investments:
U.S. government debt securities	$	15,852	$	6	$	(2	)	$	15,856
Corporate notes		14,471		8		(4	)		14,475
Certificates of deposit		467		—		—			467
Total short-term investments	$	30,790	$	14	$	(6	)	$	30,798
Long-term investments:
U.S. government debt securities	$	6,330	$	2	$	—		$	6,332
Corporate notes		1,050		1		—			1,051
Total long-term investments	$	7,380	$	3	$	—		$	7,383

	2011
	Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash and cash equivalents	$	40,025	$	—	$	—		$	40,025
Short-term investments:
U.S. government debt securities	$	4,834	$	2	$	—		$	4,836
Corporate notes		4,578		1		(2	)		4,577
Total short-term investments	$	9,412	$	3	$	(2	)	$	9,413
Long-term investments:
U.S. government debt securities	$	5,721	$	1	$	(1	)	$	5,721
Corporate notes		2,816		2		(2	)		2,816
Total long-term investments	$	8,537	$	3	$	(3	)	$	8,537

Schedule of cost and fair value of investments based on maturity groups

   Cost and fair value of investments based on two maturity groups at December 31, 2011 and 2010 were as follows (in thousands):

	2012
	Cost		Unrealized Gains		Unrealized Losses			Fair Value
Due within 1 year	$	30,790	$	14	$	(6	)	$	30,798
Due in 1-2 years		7,380		3		—			7,383
Total	$	38,170	$	17	$	(6	)	$	38,181

	2011
	Cost		Unrealized Gains		Unrealized Losses			Fair Value
Due within 1 year	$	9,412	$	3	$	(2	)	$	9,413
Due in 1-2 years		8,537		3		(3	)		8,537
Total	$	17,949	$	6	$	(5	)	$	17,950

Schedule of fair value hierarchy for financial assets (cash equivalents and investments)

The following table represents the Company's fair value hierarchy for its financial assets (cash equivalents and investments) as of December 31, 2012 and 2011 (in thousands):

	2012
	Fair Value		Level 1		Level 2		Level 3
Money market funds	$	1,407	$	1,407	$	—	$	—
U.S. government debt securities		22,289		—		22,289		—
Corporate notes		16,226		—		16,226		—
Certificates of deposit		467		—		467		—
Total assets	$	40,389	$	1,407	$	38,982	$	—

	2011
	Fair Value		Level 1		Level 2		Level 3
Money market funds	$	2,792	$	2,792	$	—	$	—
Corporate notes		7,393		—		7,393		—
U.S. government debt securities		10,557		—		10,557		—
Total assets	$	20,742	$	2,792	$	17,950	$	—

Summary of changes in fair value of the Company's acquisition-related earn-out liabilities measured at fair value using significant unobservable inputs (Level 3)

	Fair Value
Balance at December 31, 2010	$	1,000
Payment of earn-out		(1,000	)
Balance at December 31, 2011	$	—