Investment Operations Realized Gains (Losses) - Recorded in Income (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Gain (Loss) on Securities [Line Items]
Realized Gain (Loss) on Disposition of Other Financial Assets	$ 0	$ (5)	$ (4)	$ (18)
Realized Gains (Loss) on sales of investments	(161)	1,707	5,607	1,777
Net realized capital gains on sales of investments	377	841	10,534	(906)
Net impairment loss recognized in earnings	0	0	(869)	(1,040)
Realized gains (losses) on investments recorded in income	377	841	9,665	(1,946)
Proceeds from Sale of Available-for-sale Securities			22,200	56,300
Cost-method Investments
Gain (Loss) on Securities [Line Items]
Gain (Loss) on Sales of Loans, Net	0	0	2,778	0
Debt Securities \| Categories of Investments, Marketable Securities, Available-for-sale Securities
Gain (Loss) on Securities [Line Items]
Gross gains - fixed maturities - available for sale	143	1,713	3,137	1,796
Available-for-sale Securities, Gross Realized Losses	304	1	304	1
Equity Securities \| Categories of Investments, Marketable Securities, Available-for-sale Securities
Gain (Loss) on Securities [Line Items]
Net realized capital gains on sales of investments	463	(866)	4,882	(2,683)
Realized Gain (Loss) on sales of Equity Securities	75	0	45	0
Other credit-related
Gain (Loss) on Securities [Line Items]
Net impairment loss recognized in earnings	0	0	(869)	(1,040)
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 Net Income	$ 538	$ (866)	$ 4,927	$ (2,683)

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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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Amount of gain (loss) on disposal of other assets utilized in financial service operations.

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Amount of realized and unrealized gain (loss) on investment.

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This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

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The net gain (loss) resulting from a sale of loans, including adjustments to record loans classified as held-for-sale at the lower-of-cost-or-market and fair value adjustments to loan held for investment purposes.

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Amount of the effect of a change in accounting principle on operating profit or loss.

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The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

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Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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