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 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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Fair Value (Fair Value Measurements Using Significant Unobservable Inputs For Equity Index Put Option Contracts) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Common Stock [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period
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
Balance, end of period	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 liabilities still held at the reporting date
Equity Index Put Option Contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	20,958	8,727	5,584	11,958
Total (gains) or losses (realized/unrealized) Included in earnings	11,869	353	(3,504)	3,584
Total (gains) or losses (realized/unrealized) Included in other comprehensive income (loss)
Purchases, issuances and settlements
Transfers in and/or (out) of Level 3
Balance, end of period	9,088	8,374	9,088	8,374
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 liabilities still held at the reporting date