Fair Value Disclosure (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gain (loss) on equity securities	$ 628	$ 518
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]
Unrealized gain (loss) on equity securities	100	1,200
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]
Unrealized gain (loss) on equity securities	$ 600	$ (700)
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 | Bellaire
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities cost			$ 5,000