Investments - Summary of Proceeds and Gains (Losses) Realized on Securities (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Proceeds received, Fixed maturity securities	$ 442,015	$ 100,129	$ 501,739	$ 190,023
Proceeds received, Equity securities	1,633	3,735	17,122	5,783
Investment gain realized on transfer			135,300
Reinsurance block of in-force fixed and variable annuity business	2,900,000		2,900,000
Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Gross gains realized	147,774	2,352	148,316	4,022
Gross losses realized	(5,976)	(1,584)	(6,081)	(1,637)
Equity securities
Debt Securities, Available-for-sale [Line Items]
Gross gains realized	389	977	5,134	1,593
Gross losses realized	$ (166)	$ (147)	$ (510)	$ (181)

Investment Gain (Loss) On Reinsurance

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- Definition

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

+ References

No definition available.

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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.

+ References

No definition available.

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- Definition

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).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26853-111562

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3151-108585

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585

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The cash inflow associated with the sale of equity securities classified as available-for-sale securities.

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- Definition

Amount before valuation allowance recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

+ References

No definition available.

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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.

+ References

No definition available.

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