Sch III Supplementary Insurance Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Deferred Policy Acquisition Cost		$ 289,456		$ 418,802		$ 302,611
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Liability for Future Policy Benefit, Loss, Claim and Loss Expense		7,424,987		7,230,853		7,078,616
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Unearned Premium		15,445		25,916		16,324
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Policy Claim and Benefit Payable		550,373		563,879		589,653
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Premium Revenue		324,976		321,101		308,266
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Net Investment Income		424,998		394,618		415,199
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Benefit, Claim, Loss and Settlement Expenses		451,127		428,962		424,901
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Amortization of Deferred Policy Acquisition Cost		22,887		33,137		22,507
Deferred Policy Acquisition Cost, Amortization Expense, Unrealized Investment Gains (Losses)	[1]	(345)		1,598		639
Deferred Policy Acquisition Cost, Amortization Expense, Net Investment Gains (Losses)	[1]	241		(184)		(240)
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Operating Expense		117,737		118,918		112,371
Annuity
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Deferred Policy Acquisition Cost		88,295		93,819		92,116
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Liability for Future Policy Benefit, Loss, Claim and Loss Expense		4,105,054		4,036,152		3,963,187
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Unearned Premium		0		0		0
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Policy Claim and Benefit Payable		335,222		338,646		355,877
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Premium Revenue		6,681		5,173		4,484
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Net Investment Income		205,857		218,823		219,700
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Benefit, Claim, Loss and Settlement Expenses		118,085		124,015		122,224
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Amortization of Deferred Policy Acquisition Cost		16,374		11,243		8,506
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Operating Expense		25,245		25,892		24,633
Life Insurance
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Deferred Policy Acquisition Cost		341,143		308,937		287,421
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Liability for Future Policy Benefit, Loss, Claim and Loss Expense		2,872,119		2,776,656		2,677,519
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Unearned Premium		22,025		19,427		17,043
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Policy Claim and Benefit Payable		188,220		194,879		201,693
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Premium Revenue		274,605		272,797		260,780
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Net Investment Income		158,230		158,003		158,318
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Benefit, Claim, Loss and Settlement Expenses		270,916		276,571		264,657
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Amortization of Deferred Policy Acquisition Cost		2,819		15,264		14,368
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Operating Expense		84,596		84,389		78,313
Corporate and Other
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Deferred Policy Acquisition Cost		60,245		62,778		70,247
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Liability for Future Policy Benefit, Loss, Claim and Loss Expense		417,172		416,403		419,411
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Unearned Premium		11,445		11,623		11,986
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Policy Claim and Benefit Payable		26,931		30,354		32,083
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Premium Revenue		42,284		43,622		43,517
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Net Investment Income		34,302		33,272		34,918
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Benefit, Claim, Loss and Settlement Expenses		39,180		34,465		39,060
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Amortization of Deferred Policy Acquisition Cost		1,801		8,869		488
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Operating Expense		7,896		8,637		9,425
Scenario, Adjustment
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Deferred Policy Acquisition Cost		(200,227)		(46,732)		(147,173)
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Liability for Future Policy Benefit, Loss, Claim and Loss Expense		30,642		1,642		18,499
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Unearned Premium		(18,025)		(5,134)		(12,705)
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Policy Claim and Benefit Payable		0		0		0
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Premium Revenue		1,404		(310)		0
Unearned revenue reserve, amortization due to realized gains		2	[2]	(181)	[2]	(515)
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Net Investment Income		0	[2]	0	[2]	0
Investment Income, Nonoperating		26,609		(15,480)		2,263
Deferred sales inducements, amortization due to unrealized gains losses		22,932		(6,065)		(1,021)
Deferred sales inducements, amortization due to realized gains losses		14	[2]	(24)	[2]	(19)
Deferred Policy Acquisition Cost, Amortization Expense, Unrealized Investment Gains (Losses)		(1,659)		1,893		639
Deferred Policy Acquisition Cost, Amortization Expense, Net Investment Gains (Losses)		234	[2]	(346)	[2]	(216)
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Operating Expense		0		0		0
Present Value of Future Profits, amortization due to realized gains losses		$ 0	[2]	$ 0	[2]	$ 0

[1] Amounts are net of adjustments, as applicable, to amortization of unearned revenue reserves, deferred acquisition costs, interest sensitive product reserves and income taxes attributable to these items

[2] Beginning in 2018, amounts include the change in fair value of equity securities due to a change in accounting guidance. See Note 1 to our consolidated financial statements for additional information.