Earnings (Loss) Per Share (Computation of Earnings (Loss) Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net income (loss) to common shareholders	$ 524,089	$ 463,215	$ (45,174)
Net income or dividends allocated to participating securities - basic and diluted	7,620	9,134	1,756
Net income (loss) allocated to common shareholders - basic and diluted	$ 516,469	$ 454,081	$ (46,930)
Weighted-average common shares - basic	86,068	86,823	86,533
Dilutive potential common shares	326	204
Weighted average common shares - diluted	86,394	87,027	86,533
Earnings (loss) per common share: Basic	$ 6.00	$ 5.23	$ (0.54)
Earnings (loss) per common share: Diluted	$ 5.98	$ 5.22	$ (0.54)