Significant Accounting Policies (Annuity Deposits (Net of Coinsurance), By Product Type) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2021 USD ($) NMOs	Dec. 31, 2020 USD ($) NMOs	Dec. 31, 2019 USD ($) NMOs
Product Information [Line Items]
Fixed index annuities	$ 3,026,211	$ 2,309,580	$ 4,603,490
Annual reset fixed rate annuities	6,000	7,846	10,665
Multi-year fixed rate annuities	2,452,994	1,295,843	47,016
Single premium immediate annuities (SPIA)	59,816	33,461	12,002
Annuity deposits, net of coinsurance	$ 5,545,021	$ 3,646,730	$ 4,673,173
Customer Concentration Risk \| Annuity Deposits Benchmark
Product Information [Line Items]
National marketing organizations, number of organizations accounting for more than 10% of annuity deposits collected \| NMOs	2	2	2
Customer Concentration Risk \| Annuity Deposits Benchmark \| National Marketing Organization, Greater than 10%, NMO 1
Product Information [Line Items]
National marketing organizations, percent of annuity deposits collected individually	14.00%	17.00%	24.00%
Customer Concentration Risk \| Annuity Deposits Benchmark \| National Marketing Organization, Greater than 10%, NMO 2
Product Information [Line Items]
National marketing organizations, percent of annuity deposits collected individually	11.00%	10.00%	14.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
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-URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13531-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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