Equity (Reclassification out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Unrealized Investment Gains (Losses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI			$ (26,350)	$ 20,591
Total reclassifications for the period
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI			(26,350)	20,591
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	$ (9,529)	$ (11,504)	26,350	(20,591)
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	(9,529)	(11,504)	26,350	(20,591)
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)	73	(1,199)	15,162	(4,898)
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)	$ (9,602)	$ (10,305)	$ 11,188	$ (15,693)