Investments (Other Invested Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Other Invested Assets [Line Items]
Other invested assets	$ 464,773	$ 94,079
LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	93,669	90,950
Derivative Instruments
Other Invested Assets [Line Items]
Other invested assets	371,104	3,129
Equity Method | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	83,878	81,002
Equity Method | Private equity | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	18,008	18,829
Equity Method | Hedge funds | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	0	0
Equity Method | Real estate-related | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	65,870	62,173
Fair Value | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	9,791	9,948
Fair Value | Private equity | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	4,089	4,028
Fair Value | Hedge funds | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	166	166
Fair Value | Real estate-related | LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	$ 5,536	$ 5,754