Unaudited Interim Statements of Financial Position - USD ($) $ in Thousands	Mar. 31, 2020		Dec. 31, 2019
Statement of Financial Position [Abstract]
Short-term Debt	$ 234,178		$ 242,094
ASSETS
Fixed maturities, available-for-sale, at fair value (amortized cost, 2020: $13,264,558; 2019: $12,465,746; 2020-net of $186 allowance for credit losses)	15,212,476		13,202,365
Fixed maturities, trading, at fair value (amortized cost, 2020: $347,115; 2019: $349,428)	432,020		383,198
Equity securities, at fair value (cost, 2020: $74,271; 2019: $63,647)	76,534		67,503
Commercial mortgage and other loans (net of $6,282 and $2,663 allowance for credit losses)	1,502,846	[1]	1,471,522
Policy loans	12,251		12,366
Short-term investments	2,020,754		335,358
Other invested assets (includes $28,761 and $10,492 of assets measured at fair value at March 31, 2020 and December 31, 2019, respectively)	505,569		474,013
Total investments	19,762,450		15,946,325
Cash and cash equivalents	13,945,360		2,795,163
Deferred policy acquisition costs	4,095,019	[1]	4,455,683
Accrued investment income	107,400		102,724
Reinsurance recoverables	944,229		621,510
Income taxes	1,172,020	[1]	1,202,714
Value of business acquired	28,282		30,025
Deferred sales inducements	699,396		812,724
Receivables from parent and affiliates	63,581		62,765
Other assets	213,171		139,933
Separate account assets	26,580,684		32,665,431
TOTAL ASSETS	67,611,592		58,834,997
LIABILITIES
Future policy benefits	26,612,760		12,932,461
Policyholders’ account balances	6,596,004		6,180,359
Payables to parent and affiliates	493,084		185,156
Long-term debt	419,418		419,418
Reinsurance payables	285,038		235,318
Other liabilities	881,363	[1]	447,405
Separate account liabilities	26,580,684		32,665,431
Total liabilities	62,102,529		53,307,642
COMMITMENTS AND CONTINGENT LIABILITIES
EQUITY
Common stock, $100 par value; 25,000 shares authorized, issued and outstanding	2,500		2,500
Additional paid-in capital	4,935,936		5,142,936
Retained earnings / (accumulated deficit)	(868,873)		(46,693)
Accumulated other comprehensive income (loss)	1,439,500		428,612
Total equity	5,509,063		5,527,355
TOTAL LIABILITIES AND EQUITY	$ 67,611,592		$ 58,834,997

[1] March 31, 2020 amounts include the impacts of the January 1, 2020 adoption of ASU 2016-13. See Note 2 for details.