Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES
Net income	$ 631,777	$ 160,422	$ 495,607
Adjustments to reconcile net income to net cash provided by operating activities
Net realized investment gains	(37,719)	(18,174)
Net realized investment gains			(104,595)
Other-than-temporary impairments	6,968	1,243	13,386
Accretion of premiums, discounts and loan origination fees	(4,394)	(6,163)	(2,008)
Net capitalized interest on policy loans and mortgage loans	(34,081)	(39,262)	(32,551)
Depreciation	53,160	52,049	53,937
Interest credited to policyholders’ account balances	511,999	315,684	415,190
Charges to policyholders’ account balances	(305,256)	(285,549)	(248,526)
Deferred federal income tax expense (benefit)	78,385	(22,599)	(142,096)
Equity in earnings of unconsolidated affiliates	(103,501)	(21,281)	(86,674)
Distributions from unconsolidated affiliates	111,848	21,453	21,541
Changes in
Policyholder liabilities	145,396	288,065	320,743
Deferred policy acquisition costs	(12,749)	(71,497)	(81,484)
Reinsurance recoverables	15,645	(8,886)	(16,880)
Premiums due and other receivables	3,780	(31,360)	(19,445)
Prepaid reinsurance premiums	8,952	10,003	(599)
Accrued investment income	(12,227)	(960)	(7,347)
Current tax receivable/payable	18,893	35,315	17,252
Liability for retirement benefits	(8,454)	(69,762)	(14,127)
Fair value of option securities	(144,978)	54,951	(90,357)
Fair value of equity securities	(422,535)	107,188	0
Other, net	5,503	24,630	4,958
Net cash provided by operating activities	506,412	495,510	495,925
Proceeds from sale/maturity/prepayment of
Held-to-maturity securities	864,481	629,359	893,977
Available-for-sale securities	500,724	451,292	489,902
Equity securities	294,798	214,737	137,780
Investment real estate	66,725	11,577	67,227
Mortgage loans	837,732	812,239	811,049
Policy loans	48,079	52,606	42,580
Other invested assets	120,455	118,846	80,901
Disposals of property and equipment	69	0	554
Distributions from unconsolidated affiliates	91,325	58,287	102,000
Payment for the purchase/origination of
Held-to-maturity securities	(1,468,253)	(1,349,008)	(1,215,311)
Available-for-sale securities	(528,495)	(680,477)
Available-for-sale securities			(737,651)
Equity securities	(49,016)	(79,514)	(108,054)
Investment real estate	(24,163)	(71,732)	(33,844)
Mortgage loans	(784,408)	(1,173,189)	(1,194,672)
Policy loans	(27,722)	(26,147)	(23,325)
Other invested assets	(109,074)	(75,233)	(47,134)
Additions to property and equipment	(21,402)	(17,670)	(24,395)
Contributions to unconsolidated affiliates	(262,569)	(151,261)	(27,869)
Change in short-term investments	(190,511)	452,005	(466,539)
Change in collateral held for derivatives	107,133	(68,565)	89,981
Other, net	10,369	7,087	18,030
Net cash used in investing activities	(523,723)	(884,761)	(1,144,813)
FINANCING ACTIVITIES
Policyholders’ account deposits	1,770,646	1,717,153	2,095,734
Policyholders’ account withdrawals	(1,481,234)	(1,345,498)	(1,271,128)
Change in notes payable	20,034	505	1,377
Dividends to stockholders	(88,243)	(88,228)	(88,335)
Payments to noncontrolling interest	(20,055)	(2,354)	(2,261)
Net cash provided by financing activities	201,148	281,578	735,387
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	183,837	(107,673)	86,499
Beginning of the period	268,164	375,837	289,338
End of the period	$ 452,001	$ 268,164	$ 375,837