Equity (Net Unrealized Investment Gains (Losses) in AOCI on AFS Fixed Maturity Securities with OTTI, Allowance for Credit Losses and All Other Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 1,533,059
Ending Balance	169,756	$ 1,533,059
Net Unrealized Investment Gains (Losses) on AFS Fixed Maturity Securities with OTTI Pre-Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	0	14,309	$ (3,334)
Reclassification due to implementation of ASU 2016-13		(14,309)
Net unrealized investment gains (losses) on investments arising during the period	0	0	17,795
Reclassification adjustment for (gains) losses included in net income	0	0	(100)
Reclassification adjustment for OTTI losses excluded from net income			(52)
Reclassification due to allowance for credit losses recorded during period	0	0
Impact of net unrealized investment (gains) losses	0	0	0
Ending Balance	0	0	14,309
Net Unrealized Investment Gains (Losses) on AFS Fixed Maturity Securities with Allowance Pre-Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	2	0	0
Reclassification due to implementation of ASU 2016-13		0
Net unrealized investment gains (losses) on investments arising during the period	2,017	59	0
Reclassification adjustment for (gains) losses included in net income	(2,141)	3	0
Reclassification adjustment for OTTI losses excluded from net income			0
Reclassification due to allowance for credit losses recorded during period	125	(60)
Impact of net unrealized investment (gains) losses	0	0	0
Ending Balance	3	2	0
Net Unrealized Investment Gains (Losses) on All Other Investments Pre Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	2,369,107	722,621	(413,575)
Reclassification due to implementation of ASU 2016-13		14,309
Net unrealized investment gains (losses) on investments arising during the period	(794,548)	1,623,552	1,139,167
Reclassification adjustment for (gains) losses included in net income	(1,334,078)	8,565	(3,023)
Reclassification adjustment for OTTI losses excluded from net income			52
Reclassification due to allowance for credit losses recorded during period	(125)	60
Impact of net unrealized investment (gains) losses	0	0	0
Ending Balance	240,356	2,369,107	722,621
Deferred Policy Acquisition Costs and Other Costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(363,429)	(156,175)	7,386
Reclassification due to implementation of ASU 2016-13		0
Net unrealized investment gains (losses) on investments arising during the period	0	0	0
Reclassification adjustment for (gains) losses included in net income	0	0	0
Reclassification adjustment for OTTI losses excluded from net income			0
Reclassification due to allowance for credit losses recorded during period	0	0
Impact of net unrealized investment (gains) losses	347,705	(207,254)	(163,561)
Ending Balance	(15,724)	(363,429)	(156,175)
Future Policy Benefits and Other Liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(63,159)	(35,983)	1,045
Reclassification due to implementation of ASU 2016-13		0
Net unrealized investment gains (losses) on investments arising during the period	0	0	0
Reclassification adjustment for (gains) losses included in net income	0	0	0
Reclassification adjustment for OTTI losses excluded from net income			0
Reclassification due to allowance for credit losses recorded during period	0	0
Impact of net unrealized investment (gains) losses	55,940	(27,176)	(37,028)
Ending Balance	(7,219)	(63,159)	(35,983)
Income Tax Benefit (Expense)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(408,754)	(115,226)	85,183
Reclassification due to implementation of ASU 2016-13		0
Net unrealized investment gains (losses) on investments arising during the period	166,868	(341,050)	(243,237)
Reclassification adjustment for (gains) losses included in net income	280,177	(1,800)	657
Reclassification adjustment for OTTI losses excluded from net income			0
Reclassification due to allowance for credit losses recorded during period	0	0
Impact of net unrealized investment (gains) losses	(84,772)	49,322	42,171
Ending Balance	(46,481)	(408,754)	(115,226)
Accumulated Other Comprehensive Income (Loss) Related to Net Unrealized Investment Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	1,533,767	429,546	(323,295)
Reclassification due to implementation of ASU 2016-13		0
Net unrealized investment gains (losses) on investments arising during the period	(625,663)	1,282,561	913,725
Reclassification adjustment for (gains) losses included in net income	(1,056,042)	6,768	(2,466)
Reclassification adjustment for OTTI losses excluded from net income			0
Reclassification due to allowance for credit losses recorded during period	0	0
Impact of net unrealized investment (gains) losses	318,873	(185,108)	(158,418)
Ending Balance	$ 170,935	$ 1,533,767	$ 429,546