Earnings (Loss) Per Share (Tables)

12 Months Ended

Dec. 31, 2021

Earnings Per Share [Abstract]

Computation of Earnings (Loss) Per Common Share

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

	Years Ended December 31,
($ in thousands, except per share data)	2021		2020			2019
Numerator:
Net income (loss) to common shareholders	$	463,215	$	(45,174	)	$	327,380
Net income or dividends allocated to participating securities - basic    and diluted		9,134		1,756			5,546
Net income (loss) allocated to common shareholders - basic and diluted	$	454,081	$	(46,930	)	$	321,834
Denominator:
Weighted-average common shares - basic		86,823		86,533			86,488
Dilutive potential common shares		204		—			111
Weighted average common shares - diluted		87,027		86,533			86,599
Earnings (loss) per common share:
Basic	$	5.23	$	(0.54	)	$	3.72
Diluted	$	5.22	$	(0.54	)	$	3.72