Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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Amount of gain (loss) recognized in other comprehensive income (OCI) from liability measured at fair value on recurring basis using unobservable input (level 3).

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Amount of purchases, (sales), issuances and (settlements) of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfers of financial instrument classified as a liability into (out of) level 3 of the fair value hierarchy.

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Fair Value (Fair Value Measurements Using Significant Unobservable Inputs) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance
Total gains or (losses) (realized/unrealized) Included in earnings
Total gains or (losses) (realized/unrealized) Included in other comprehensive income (loss)
Purchases, issuances and settlements	9,877		9,877
Transfers in and/or (out) of Level 3
Ending Balance	9,877		9,877
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date
Other Invested Assets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	2,425,061	1,767,963	1,982,582	1,717,336
Total gains or (losses) (realized/unrealized) Included in earnings	(639,058)	125,025	(196,579)	175,652
Total gains or (losses) (realized/unrealized) Included in other comprehensive income (loss)
Purchases, issuances and settlements
Transfers in and/or (out) of Level 3
Ending Balance	1,786,003	1,892,988	1,786,003	1,892,988
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at the reporting date