Earnings per Share Earnings per Share (Tables)

12 Months Ended

Dec. 31, 2020

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 RSUs and options to purchase common stock:

	Year ended December 31,
	2020	2019	2018
Weighted average common shares—basic	43,581,232	45,303,659	45,824,555
Dilutive effect of restricted stock units	—	224,946	242,204
Dilutive effect of stock options	—	66,549	103,705
Weighted average common shares—diluted	43,581,232	45,595,154	46,170,464