Earnings Per Share Attributable to Common Stockholders (Tables)

9 Months Ended

Sep. 30, 2016

Earnings Per Share [Abstract]

Computation of Basic and Diluted Net Income Per Share

The following tables present the calculation of basic and diluted net income per share attributable to common stockholders for the three and nine months ended September 30, 2016 and 2015:

	Three Months Ended September 30, 2016						Three Months Ended September 30, 2015
	Income (Numerator)		Shares (Denominator)		Per  Share Amount		Income (Numerator)		Shares (Denominator)		Per  Share Amount
	(in thousands, except per share data)
Basic EPS
Net income attributable to common stockholders	$	13,182		85,217	$	0.15	$	6,867		84,583	$	0.08
Effect of Dilutive Securities
Stock options		—		776				—		1,267
Restricted stock units and restricted stock awards		—		431				—		17
Diluted EPS
Net income attributable to common stockholders	$	13,182		86,424	$	0.15	$	6,867		85,867	$	0.08

	Nine Months Ended September 30, 2016						Nine Months Ended September 30, 2015
	Income (Numerator)		Shares (Denominator)		Per  Share Amount		Income (Numerator)		Shares (Denominator)		Per  Share Amount
	(in thousands, except per share data)
Basic EPS
Net income attributable to common stockholders	$	35,920		84,889	$	0.42	$	26,789		83,827	$	0.32
Effect of Dilutive Securities
Stock options		—		837				—		1,761
Restricted stock units and restricted stock awards		—		231				—		11
Diluted EPS
Net income attributable to common stockholders	$	35,920		85,957	$	0.42	$	26,789		85,599	$	0.31

Anti-dilutive Securities Excluded from Calculation of Diluted Net Income Per Share

The number of shares of common stock underlying stock-based awards excluded from the calculation of diluted net income per share attributable to common stockholders because their effect would have been antidilutive for the three and nine months ended September 30, 2016 and 2015 were as follows:  

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Anti-dilutive shares underlying stock-based awards:
Stock options		916,154		1,725,267		916,154		1,517,215
Restricted stock awards		—		—		—		—
Restricted stock units		178,551		88,063		178,551		—