Policyholders' Liabilities (Guaranteed Minimum Crediting Rate) (Details) $ in Thousands	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)		Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 47,608,155	$ 41,912,536	[1]	$ 39,204,409
1 - 50 bps above guaranteed minimum | Minimum
Policyholder Account Balance [Line Items]
Policyholder account balance above guaranteed minimum crediting rate	1			1
1 - 50 bps above guaranteed minimum | Maximum
Policyholder Account Balance [Line Items]
Policyholder account balance above guaranteed minimum crediting rate	50			50
51 - 150 bps above guaranteed minimum | Minimum
Policyholder Account Balance [Line Items]
Policyholder account balance above guaranteed minimum crediting rate	51			51
51 - 150 bps above guaranteed minimum | Maximum
Policyholder Account Balance [Line Items]
Policyholder account balance above guaranteed minimum crediting rate	150			150
Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Policyholder account balance above guaranteed minimum crediting rate	150			150
Variable Annuities
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 3,081,376	16,432,032		$ 3,361,321	$ 11,465,411
Variable Annuities | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	2,219,055			2,463,095
Variable Annuities | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	842,771			879,281
Variable Annuities | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	19,548			18,943
Variable Annuities | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	2			2
Variable/Universal Life
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	17,506,563	$ 18,736,365		16,577,232	$ 18,762,548
Variable/Universal Life | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	6,899,826			7,085,677
Variable/Universal Life | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	3,384,953			11,776
Variable/Universal Life | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	6,582,586			5,263,150
Variable/Universal Life | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 639,198			$ 4,216,629
Less than 1.00% | Variable Annuities
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	1.00%			1.00%
Account Values with Crediting Rates	$ 1,825,128			$ 1,947,289
Less than 1.00% | Variable Annuities | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	972,976			1,050,808
Less than 1.00% | Variable Annuities | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	833,696			877,536
Less than 1.00% | Variable Annuities | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	18,454			18,943
Less than 1.00% | Variable Annuities | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 2			$ 2
Less than 1.00% | Variable/Universal Life
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	1.00%			1.00%
Account Values with Crediting Rates	$ 9,078			$ 16,033
Less than 1.00% | Variable/Universal Life | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			16,033
Less than 1.00% | Variable/Universal Life | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
Less than 1.00% | Variable/Universal Life | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
Less than 1.00% | Variable/Universal Life | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	9,078			0
1.00% - 1.99% | Variable Annuities
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 232,269			$ 253,671
1.00% - 1.99% | Variable Annuities | Minimum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	1.00%			1.00%
1.00% - 1.99% | Variable Annuities | Maximum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	1.99%			1.99%
1.00% - 1.99% | Variable Annuities | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 229,049			$ 251,989
1.00% - 1.99% | Variable Annuities | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	2,126			1,682
1.00% - 1.99% | Variable Annuities | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	1,094			0
1.00% - 1.99% | Variable Annuities | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
1.00% - 1.99% | Variable/Universal Life
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 3,233,287			$ 3,014,015
1.00% - 1.99% | Variable/Universal Life | Minimum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	1.00%			1.00%
1.00% - 1.99% | Variable/Universal Life | Maximum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	1.99%			1.99%
1.00% - 1.99% | Variable/Universal Life | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 163,616			$ 340,859
1.00% - 1.99% | Variable/Universal Life | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
1.00% - 1.99% | Variable/Universal Life | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	2,706,552			694,771
1.00% - 1.99% | Variable/Universal Life | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	363,119			1,978,385
2.00% - 2.99% | Variable Annuities
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 28,621			$ 30,913
2.00% - 2.99% | Variable Annuities | Minimum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	2.00%			2.00%
2.00% - 2.99% | Variable Annuities | Maximum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	2.99%			2.99%
2.00% - 2.99% | Variable Annuities | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 24,531			$ 30,850
2.00% - 2.99% | Variable Annuities | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	4,090			63
2.00% - 2.99% | Variable Annuities | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
2.00% - 2.99% | Variable Annuities | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
2.00% - 2.99% | Variable/Universal Life
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 4,453,270			$ 4,368,221
2.00% - 2.99% | Variable/Universal Life | Minimum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	2.00%			2.00%
2.00% - 2.99% | Variable/Universal Life | Maximum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	2.99%			2.99%
2.00% - 2.99% | Variable/Universal Life | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 21,001			$ 8,519
2.00% - 2.99% | Variable/Universal Life | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	1,399,691			0
2.00% - 2.99% | Variable/Universal Life | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	2,765,577			2,259,847
2.00% - 2.99% | Variable/Universal Life | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	267,001			2,099,855
3.00% - 4.00% | Variable Annuities
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 993,267			$ 1,127,302
3.00% - 4.00% | Variable Annuities | Minimum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	3.00%			3.00%
3.00% - 4.00% | Variable Annuities | Maximum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	4.00%			4.00%
3.00% - 4.00% | Variable Annuities | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 990,408			$ 1,127,302
3.00% - 4.00% | Variable Annuities | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	2,859			0
3.00% - 4.00% | Variable Annuities | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
3.00% - 4.00% | Variable Annuities | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
3.00% - 4.00% | Variable/Universal Life
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 7,651,711			$ 7,084,665
3.00% - 4.00% | Variable/Universal Life | Minimum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	3.00%			3.00%
3.00% - 4.00% | Variable/Universal Life | Maximum
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	4.00%			4.00%
3.00% - 4.00% | Variable/Universal Life | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 4,555,992			$ 4,625,968
3.00% - 4.00% | Variable/Universal Life | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	1,985,262			11,776
3.00% - 4.00% | Variable/Universal Life | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	1,110,457			2,308,532
3.00% - 4.00% | Variable/Universal Life | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 0			$ 138,389
Greater than 4.00% | Variable Annuities
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	4.00%			4.00%
Account Values with Crediting Rates	$ 2,091			$ 2,146
Greater than 4.00% | Variable Annuities | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	2,091			2,146
Greater than 4.00% | Variable Annuities | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
Greater than 4.00% | Variable Annuities | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
Greater than 4.00% | Variable Annuities | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 0			$ 0
Greater than 4.00% | Variable/Universal Life
Policyholder Account Balance [Line Items]
Range of Guaranteed Minimum Crediting Rates	4.00%			4.00%
Account Values with Crediting Rates	$ 2,159,217			$ 2,094,298
Greater than 4.00% | Variable/Universal Life | At guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	2,159,217			2,094,298
Greater than 4.00% | Variable/Universal Life | 1 - 50 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
Greater than 4.00% | Variable/Universal Life | 51 - 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	0			0
Greater than 4.00% | Variable/Universal Life | Greater than 150 bps above guaranteed minimum
Policyholder Account Balance [Line Items]
Account Values with Crediting Rates	$ 0			$ 0

[1] Prior period amounts adjusted for the implementation of Accounting Standard Update ("ASU") 2018-12: Targeted Improvements to the Accounting for Long-Duration Contracts.