Earnings Per Common Share (Computation of Earnings Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Earnings Per Share [Abstract]
Net income to common shareholders	$ 119,504	$ 108,612
Net income allocated to participating securities - basic and diluted	521	784
Net income allocated to common shareholders - basic	118,983	107,828
Net income allocated to common shareholders - diluted	$ 118,983	$ 107,828
Weighted-average common shares - basic	86,092	86,521
Dilutive potential common shares	370	205
Weighted-average common shares - diluted	86,462	86,726
Earnings per common share: Basic	$ 1.38	$ 1.25
Earnings per common share: Diluted	$ 1.38	$ 1.24