Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 36,582	$ 51,724	$ 51,210	$ 97,595
Earnings allocated to participating securities - nonvested restricted shares	139	378	325	838
Earnings allocated to common shareholders, Basic	$ 36,443	$ 51,346	$ 50,885	$ 96,757
Weighted average common shares outstanding	70,679	72,451	70,942	72,486
Basic earnings per common share	$ 0.52	$ 0.71	$ 0.72	$ 1.33
Earnings allocated to common shareholders, Diluted	$ 36,443	$ 51,346	$ 50,885	$ 96,757
Dilutive effect of equity awards and warrants	32	0	39	1
Weighted average diluted common shares outstanding	70,711	72,451	70,981	72,487
Diluted earnings per common share	$ 0.52	$ 0.71	$ 0.72	$ 1.33
Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive.	571	0	450	0