Fair Value Measurements (Quantitative Information Level 3 Measurements ) (Details) - Level 3 - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Convertible preferred securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	$ 20,628	$ 15,424	$ 15,410	$ 16,278	$ 16,946	$ 16,803	$ 15,905	$ 11,618
Implied based on market prices | Convertible preferred securities | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	20,628			16,278	16,946
Third party appraisal | Grain Assets | Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset fair value	$ 0			$ 9,000	$ 0