Earnings per Share Earnings per Share (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]

Schedule of Weighted Average Number of Shares [Table Text Block]

The following table summarizes the dilutive effect of restricted shares and options to purchase common stock for the three and nine months ended September 30, 2017 and 2016:

	Three months ended September 30,		Nine months ended September 30,
	2017	2016	2017	2016
Weighted average common shares—basic	45,721,155	45,435,936	45,669,782	45,381,592
Dilutive effect of restricted share awards	233,859	244,757	226,617	248,942
Dilutive effect of stock options	74,347	79,762	57,179	83,339
Weighted average common shares—diluted	46,029,361	45,760,455	45,953,578	45,713,873