Earnings per Share (Narrative) (Details) - USD ($)			12 Months Ended
	Feb. 07, 2025	Dec. 30, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Aug. 31, 2022	Aug. 30, 2018
Earnings per Share [Line Items]
Total anti-dilutive shares excluded from the calculation (in shares)			109,900	17,900	119,000
Number of shares repurchased, cost			$ 35,017,000	$ 25,011,000	$ 54,549,000
Unsettled repurchase shares			0	0
Retained percentage limit on value of TRS			20.00%
2018 Repurchase Program [Member]
Earnings per Share [Line Items]
Number of shares repurchased					103,010
Number of shares repurchased, cost					$ 4,500,000
2022 Repurchase Program [Member]
Earnings per Share [Line Items]
Number of shares repurchased			846,845	556,115	1,096,283
Number of shares repurchased, cost			$ 35,000,000	$ 25,000,000	$ 50,000,000
Stock repurchase program, remaining amount			90,000,000
Deltic [Member] | Special Cash Dividend [Member]
Earnings per Share [Line Items]
Dividend payable		$ 75,700,000
Dividend payable, per share		$ 0.95
Distribution, payable date		Dec. 30, 2022
Deltic [Member] | Special Cash Dividends [Member]
Earnings per Share [Line Items]
Dividend payable			$ 0
Deltic [Member] | Special Cash Dividends [Member]
Earnings per Share [Line Items]
Dividend payable				$ 0
Deltic [Member] | Subsequent Event [Member] | Cash dividend [Member]
Earnings per Share [Line Items]
Dividend payable, per share	$ 0.45
Distribution, date of declared	Feb. 07, 2025
Distribution, date of record	Mar. 07, 2025
Distribution, payable date	Mar. 31, 2025
Maximum [Member] | 2018 Repurchase Program [Member]
Earnings per Share [Line Items]
Stock repurchase program, authorized amount							$ 100,000,000.0
Maximum [Member] | 2022 Repurchase Program [Member]
Earnings per Share [Line Items]
Stock repurchase program, authorized amount						$ 200,000,000