Investments (Equity Method Investments, Statement of Financial Position) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Invested assets	$ 221,661,364	$ 208,308,100
Total Liabilities	215,706,270	204,260,384
Partners' capital	5,955,094	4,047,716
Total liabilities and partners’ capital	221,661,364	208,308,100
Equity Method Investment
Schedule of Equity Method Investments [Line Items]
Invested assets	72,416,906	12,952,942
Total Liabilities	12,120,390	90,444
Partners' capital	60,296,516	12,862,498
Total liabilities and partners’ capital	72,416,906	12,952,942
Total liabilities and partners’ capital included above	746,870	348,267
Equity in LP/LLC interests not included above	201,541	175,024
Carrying value	$ 948,411	$ 523,291