Earnings Per Share
 3 Months Ended
Mar. 31, 2015
Earnings Per Share [Abstract]  
Earnings Per Share
Earnings Per Share
Basic net income per share is calculated by dividing net income for the period by the weighted-average number of common shares outstanding during the period. Diluted net income per share is calculated by dividing net income for the period by the weighted average number of shares outstanding during the period plus the dilutive effect of our outstanding stock awards and shares issuable under our employee stock purchase plan using the treasury stock method.
The calculations of basic and diluted net income per share for the three months ended March 31, 2015 and 2014 are as follows (dollars in thousands, except for per share data):
 
Three Months Ended 
 March 31,
 
2015
 
2014
Basic:
 
 
 
Net income attributable to common stockholders
$
6,410

 
$
10,274

Weighted average number of common shares outstanding
17,302,522

 
17,054,598

Basic net income per share attributable to common stockholders
$
0.37

 
$
0.60

Diluted:
 
 
 
Net income attributable to common stockholders
$
6,410

 
$
10,274

Weighted average number of common shares outstanding
17,302,522

 
17,054,598

Weighted average number of dilutive common share equivalents from options to purchase common stock
412,891

 
512,985

Common shares and common share equivalents
17,715,413

 
17,567,583

Diluted net income per share
$
0.36

 
$
0.58


Outstanding stock options and performance stock units that have an above-market exercise price or that are anti-dilutive under the treasury stock method, are excluded from our diluted computation. As of March 31, 2015, the total number of excluded stock options and performance stock units was 349,117.