Equity (Reclassification out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Unrealized Investment Gains (Losses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI			$ (1,074,047)	$ (35,880)
Total reclassifications for the period
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI			(1,074,047)	(35,880)
Reclassification out of Accumulated Other Comprehensive Income | Net Unrealized Investment Gains (Losses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI	$ (19,773)	$ 6,401	1,074,047	35,880
Reclassification out of Accumulated Other Comprehensive Income | Total reclassifications for the period
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI	(19,773)	6,401	1,074,047	35,880
Reclassification out of Accumulated Other Comprehensive Income | Net unrealized investment gains (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net unrealized investment gains (losses)	(25,759)	8,668	1,055,745	15,090
Reclassification out of Accumulated Other Comprehensive Income | Currency/Interest Rate | Cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net unrealized investment gains (losses)	$ 5,986	$ (2,267)	$ 18,302	$ 20,790