Earnings per Share Earnings per Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Weighted average common shares—basic	43,581,232	45,303,659	45,824,555
Weighted average common shares—diluted	43,581,232	45,595,154	46,170,464
Restricted Shares [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Incremental common shares attributable to dilutive effect of share-based payment arrangements	0	224,946	242,204
Stock Options [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Incremental common shares attributable to dilutive effect of share-based payment arrangements	0	66,549	103,705