

12.	Net Income (Loss) per Share Attributable to Sterling Common Stockholders

Basic net income (loss) per share attributable to Sterling common stockholders is computed by dividing net income (loss) attributable to Sterling common stockholders by the weighted average number of common shares outstanding during the period. Diluted net income (loss) per common share attributable to Sterling common stockholders is the same as basic net income (loss) per share attributable to Sterling common stockholders but includes dilutive unvested stock and warrants using the treasury stock method. The following table reconciles the numerators and denominators of the basic and diluted per common share computations for net income (loss) attributable to Sterling common stockholders (amounts in thousands, except per share data):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2017		2016		2017		2016
Numerator:
Net income (loss) attributable to Sterling common stockholders	$	7,132	$	2,415	$	8,537	$	(2,890	)
Weighted average common shares outstanding — basic	26,486		25,003		25,787		23,915
Shares for dilutive unvested stock and warrants	434		362		473		—
Weighted average common shares outstanding and incremental shares assumed repurchased— diluted	26,920		25,365		26,260		23,915
Basic income (loss) per share attributable to Sterling common stockholders	$	0.27	$	0.10	$	0.33	$	(0.12	)
Diluted income (loss) per share attributable to Sterling common stockholders	$	0.26	$	0.10	$	0.33	$	(0.12	)

In accordance with the treasury stock method, approximately 0.3 million shares of unvested common stock were excluded from the diluted weighted average common shares outstanding for the nine months ended September 30, 2016, as the Company incurred a loss during that period and the impact of such shares would have been anti-dilutive.