Earnings per Share

9 Months Ended

Sep. 30, 2018

Earnings per Share

Net income is divided by the weighted average number of common shares outstanding during the period to calculate basic earnings per share. Diluted earnings per share is calculated to give effect to stock options and RSUs. The following table summarizes the dilutive effect of RSUs and options to purchase common stock for the three and nine months ended September 30, 2018 and 2017:



	Three months ended September 30,		Nine months ended September 30,
	2018	2017	2018	2017
Weighted average common shares—basic	45,850,288	45,721,155	45,850,187	45,669,782
Dilutive effect of restricted stock units	203,800	233,859	246,347	226,617
Dilutive effect of stock options	112,470	74,347	102,350	57,179
Weighted average common shares—diluted	46,166,558	46,029,361	46,198,884	45,953,578

In November 2015, the Company announced its Board of Directors had authorized the Company to purchase its common stock up to $50 million in the aggregate. In the three and nine months ended September 30, 2018 the Company purchased 23,191 and 124,138 shares of its outstanding common stock for approximately $0.7 million and $3.6 million, respectively. The Company did not purchase any shares of its outstanding common stock in the three and nine months ended September 30, 2017.