Investments (Other Invested Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Other Invested Assets [Line Items]
Other invested assets	$ 964,752	$ 1,209,925
Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	926,270	887,706
Company’s investment in separate accounts
Other Invested Assets [Line Items]
Other invested assets	716	53,694
Derivative Instruments
Other Invested Assets [Line Items]
Other invested assets	37,766	268,525
Equity Method | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	849,902	808,227
Equity Method | Private equity | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	306,449	286,141
Equity Method | Hedge funds | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	440,632	432,749
Equity Method | Real estate-related | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	102,821	89,337
Fair Value | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	76,368	79,479
Fair Value | Private equity | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	66,186	69,137
Fair Value | Hedge funds | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	456	481
Fair Value | Real estate-related | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	$ 9,726	$ 9,861