Equity (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares
Class of Stock [Line Items]
Number of years dividends have been paid	87 years
Dividends declared per common share (in usd per share) | $ / shares	$ 0.5100	$ 0.6950	$ 0.8750
Dividends declared on common stock | $	$ 104,786	$ 142,033	$ 178,761
Credit agreement limitation on company's subsidiaries ratio of funded debt to capitalization	0.65
Company's subsidiaries net assets restricted from use for dividend payments | $	$ 1,300,000
Common Stock
Class of Stock [Line Items]
Dividends declared on common stock | $	$ 103,900	$ 141,500	$ 177,900
K-Plan
Class of Stock [Line Items]
Common stock, authorized shares remaining (in shares) | shares	7,200,000
Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (in shares) | shares	2,000,000
Preferred stock, par value per share (in usd per share) | $ / shares	$ 100
Preferred stock, outstanding (in shares) | shares	0	0