Fair Value Disclosure (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on equity securities	$ (264)	$ 421	$ 777	$ 1,049
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	18,039		18,039		$ 17,208
Gain (loss) on equity securities	(500)	(100)	(200)	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value measurements, recurring | Bellaire
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on equity securities	300	$ 500	1,000	$ 1,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Reported Value Measurement | Fair value measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities cost						$ 2,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Reported Value Measurement | Fair value measurements, recurring | Other noncurrent assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	5,800		5,800		6,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Reported Value Measurement | Fair value measurements, recurring | Bellaire
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities cost						$ 5,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Reported Value Measurement | Fair value measurements, recurring | Bellaire | Other noncurrent assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	$ 12,200		$ 12,200		$ 11,200