Investment Operations Realized gains losses on investments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Gain (Loss) on Securities [Line Items]
Other		$ (4)	$ (19)		$ 40
Gain (Loss) on sale of Investments, Excluding Other than Temporary Impairments		2,830	1,813		599
Gain (Loss) on Investments, Excluding Other than Temporary Impairments		8,523	(7,276)		599
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net		(919)	(4,998)		(1,553)
Net realized gains (losses) on investments recorded in income		7,604	(12,274)		(954)
Proceeds from Sale of Debt Securities, Available-for-sale		34,600	82,900		58,700
Credit-related portion of fixed maturity losses (2)
Gain (Loss) on Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net		0	(32)	[1]	0
Other credit-related (3)
Gain (Loss) on Securities [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	[2]	(919)	(4,966)		(1,553)
Categories of Investments, Cost-method Investments
Gain (Loss) on Securities [Line Items]
Mortgage loans		2,778	0		0
Real estate		54	0		304
Debt Securities | Categories of Investments, Marketable Securities, Available-for-sale Securities
Gain (Loss) on Securities [Line Items]
Gross gains		3,779	2,195		1,426
Gross losses		(3,777)	(363)		(1,081)
Equity Securities | Categories of Investments, Marketable Securities, Available-for-sale Securities
Gain (Loss) on Securities [Line Items]
Equity securities		27	(952)		$ (90)
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	[3]	5,666	(8,137)
Accounting Standards Update 2016-01 | Equity Securities | Categories of Investments, Marketable Securities, Available-for-sale Securities
Gain (Loss) on Securities [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results		$ 5,693	$ (9,089)

[1] Amount represents the credit-related losses recognized for fixed maturities that were impaired through income but not written down to fair value. As discussed above, the non-credit portion of the losses have been recognized in other comprehensive income (loss).

[2] Amount represents credit-related losses for fixed maturities, mortgage loans, and other investments written down to fair value through income.

[3] See Note 1 to our consolidated financial statements for discussion of change in accounting policy for equity securities during 2018.