Deferred Transaction Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning of year	$ 569,839	$ 382,080	$ 723,972
Deferrals	45,444	77,306	69,857
Amortization, excluding unlocking, net of interest	(101,477)	(84,349)	(107,917)
Unlocking	(559)	36,510	(22,358)
Adjustments related to unrealized (gains) losses	416,397	158,292	(261,186)
Reinsurance	(19,858)	0	(20,288)
Deferred policy acquisition costs, end of year	909,786	569,839	382,080
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning of year	78,136	43,845	104,359
Deferrals	4,039	18,118	10,344
Amortization, excluding unlocking, net of interest	(14,130)	(14,755)	(18,363)
Unlocking	99	993	(4,445)
Adjustments related to unrealized (gains) losses	57,498	29,935	(43,557)
Reinsurance	(11,243)	0	(4,493)
Deferred sales inducements, end of year	114,399	78,136	43,845
Movement Analysis Of Value Of Business Acquired [Roll Forward]
VOBA, beginning of year	154,499	162,968	138,071
Business acquired	0	0	0
Other increase	0	0	35,125
Amortization, excluding unlocking	(8,005)	(8,469)	(10,228)
Unlocking	0	0	0
VOBA, end of year	146,494	154,499	162,968
Present Value of Future Insurance Profits, Amortization Expense [Abstract]
2023	7,673
2024	7,363
2025	7,172
2026	7,030
2027	6,823
Cost of Reinsurance [Abstract]
Balance, beginning of year	89,686	102,840	0
Additions	0	0	102,840
Amortization	(11,358)	(13,154)	0
Balance as of end of year	$ 78,328	$ 89,686	$ 102,840