Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2019

A summary of the information used in the computation of earnings per common share follows.

	Years Ended December 31,
($ in thousands, except per share data)	2019		2018		2017
Numerator:
Net income to common shareholders	$	327,380	$	323,770	$	215,632
Net income allocated to participating securities -- basic and diluted		5,546		5,930		4,670
Net income allocated to common shareholders - basic and diluted	$	321,834	$	317,840	$	210,962
Denominator:
Weighted-average common shares - basic		86,488		85,355		84,695
Dilutive potential common shares		111		166		268
Weighted average common shares - diluted		86,599		85,521		84,963
Earnings per common share:
Basic	$	3.72	$	3.72	$	2.49
Diluted	$	3.72	$	3.72	$	2.48