Significant Accounting Policies - Other Asset Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Other asset investments	$ 90,182	$ 37,144
Other assets | Funded investments
Schedule of Equity Method Investments [Line Items]
Other asset investments	37,417	20,368
Other liabilities
Schedule of Equity Method Investments [Line Items]
Unfunded investment obligations	(52,765)	(16,776)
Other liabilities | Unfunded investments
Schedule of Equity Method Investments [Line Items]
Other asset investments	$ 52,765	$ 16,776