Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2012

Earnings Per Share [Abstract]

Computation of basic and diluted net income per share under the two-class method attributable to common stockholders

	Three months ended September 30,					Nine months  ended September 30,
	2012		2011			2012			2011
	(in thousands, except per share amounts)
Numerator:
Net income	$	3,664	$	2,401		$	12,158		$	13,934
Non-cumulative dividends to holders of preferred stock		—		(1,498	)		(2,248	)		(4,495	)
Undistributed earnings allocable to holders of preferred stock		—		(840	)		(3,709	)		(8,821	)
Net income—basic		3,664		63			6,201			618
Adjustment for undistributed earnings reallocated to holders of common stock		—		145			521			1,221
Net income—diluted	$	3,664	$	208		$	6,722		$	1,839
Denominator:
Weighted average shares used in computing net income per share:
Basic		20,342		982			10,956			925
Weighted average effect of potentially dilutive securities:
Options to purchase common stock		2,699		2,820			2,789			2,271
Employee stock purchase plan		117		—			70			—
Common stock warrants		1		—			1			—
Convertible preferred stock warrants		—		—			—			—
Diluted		23,159		3,802			13,816			3,196
Net income per share:
Basic	$	0.18	$	0.06		$	0.57		$	0.67
Diluted	$	0.16	$	0.05		$	0.49		$	0.58

Anti-dilutive shares excluded from computation of diluted net earnings loss per share

	Three months  ended September 30,				Nine months  ended September 30,
	2012		2011		2012		2011
	(in thousands)
Options to purchase common stock		923		—		345		—
Convertible preferred stock (if-converted basis)		—		13,205		6,506		13,205
Restricted stock units		18		—		18		—
Total		941		13,205		6,869		13,205