Investments (Other Invested Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Other Invested Assets [Line Items]
Other invested assets	$ 1,008,769	$ 1,209,925
Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	997,970	887,706
Company’s investment in separate accounts
Other Invested Assets [Line Items]
Other invested assets	573	53,694
Derivative Instruments
Other Invested Assets [Line Items]
Other invested assets	10,226	268,525
Equity Method | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	926,564	808,227
Equity Method | Private equity | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	291,802	286,141
Equity Method | Hedge funds | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	530,458	432,749
Equity Method | Real estate-related | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	104,304	89,337
Fair Value | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	71,406	79,479
Fair Value | Private equity | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	61,474	69,137
Fair Value | Hedge funds | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	433	481
Fair Value | Real estate-related | Total LPs/LLCs
Other Invested Assets [Line Items]
Other invested assets	$ 9,499	$ 9,861