Earnings Per Common Share (Computation of Earnings Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Earnings Per Share [Abstract]
Net income to common shareholders	$ 113,531	$ 114,557	$ 233,035	$ 223,169
Net income allocated to participating securities - basic and diluted	486	810	1,007	1,594
Net income allocated to common shareholders - basic	113,045	113,747	232,028	221,575
Net income allocated to common shareholders - diluted	$ 113,045	$ 113,747	$ 232,028	$ 221,575
Weighted-average common shares - basic	85,577	86,510	85,833	86,515
Dilutive potential common shares	366	255	370	253
Weighted-average common shares - diluted	85,943	86,765	86,203	86,768
Earnings per common share: Basic	$ 1.32	$ 1.31	$ 2.7	$ 2.56
Earnings per common share: Diluted	$ 1.32	$ 1.31	$ 2.69	$ 2.55