Common Shares, Redeemable Common Shares and Preferred Shares Common shares outstanding (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) shares
Stock split, conversion ratio	2
Preferred shares
Preferred stock, shares authorized	4,000,000
Preferred stock, par value | $ / shares	$ 0
Preferred stock, shares issued	0
Common stock, number of shares, par value and other disclosures [Abstract]
Common stock, shares authorized	96,000,000	96,000,000
Redeemable stock, outstanding	8,499,086	9,188,010
Common stock, par value (in dollars per share) | $ / shares	$ 0.50	$ 0.50
Common stock, shares issued	77,328,434	76,639,510	76,435,752
Treasury stock, shares	44,480,126	43,110,036	41,325,298
Shares purchased, value | $	$ 78,076	$ 75,694	$ 50,946
Common shares, direct sales	151,055
Common shares, value, direct sales | $	$ 5,226
Stock issued during period, shares, employee benefit plan	721,546
Stock issued during period, value, employee retirement plan | $	$ 14,000
Common shares, employer matching contribution, shares	526,147
Employee retirement plan, employer match | $	$ 10,240
Accrued 401K match | $	$ 2,447
Stock issued during period, shares, employee stock purchase plan	615,917
Increase (decrease) in stockholders' equity [Roll Forward]
Shares outstanding, beginning of year	42,717,484	44,502,222
Shares purchased	(3,972,974)	(4,165,582)
Shares sold	2,014,365	1,771,075
Stock subscription offering, employee cash purchases	13,662	152,800
Options exercised	574,857	456,969
Shares outstanding, end of year	41,347,394	42,717,484	44,502,222
Stock subscription offering, number of partially-paid subscriptions	1,259,250
Stock subscription offering, number of rights outstanding	455,754
Per share amounts and common shares outstanding [Abstract]
Share-based compensation arrangement by share-based payment award, options, exercisable, number	1,488,455
Stock subscription offering, number of rights outstanding	455,754
Treasury stock [Member]
Common stock, number of shares, par value and other disclosures [Abstract]
Shares purchased, value | $	$ 78,076	$ 75,694	$ 50,946
Employee stock option
Per share amounts and common shares outstanding [Abstract]
Share-based compensation arrangement by share-based payment award, options, exercisable, number	1,488,455