Earnings per Share Earnings per Share (Details) - shares	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Weighted average common shares—basic	44,868,503	45,175,244	45,592,075	45,578,815	45,747,659	45,850,288	45,920,307	45,779,966	45,303,659	45,824,555	45,682,627
Weighted average common shares—diluted	45,144,353	45,415,767	45,828,315	45,992,182	46,085,202	46,166,558	46,200,757	46,229,337	45,595,154	46,170,464	45,990,252
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									224,946	242,204	241,974
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									66,549	103,705	65,651