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Investments (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended
Investments (Narrative) (Details) - USD ($) $ in Thousands	Sep. 25, 2017	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale		$ 0
Variable interest entity, amount committed to invest	$ 200,000
Variable interest entity, ownership percentage	76.60%
Annual management fee percentage	2.00%
Entitled carried interest percentage	20.00%
Investment period	6 years
Equity securities		121,552		$ 122,593
Variable interest entity, amount of capital call notices received			$ 7,100
Variable interest entity, amount paid			8,100
Distribution from equity method investment		0
Income (loss) from equity method investment		(785)	24,270
Management fees recognized		$ 800	$ 800
Fund
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 128,800