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Investments (Components Of Net Realized and Unrealized Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on disposals of securities, fixed income securities (excluding OTTI charges)	$ 20,425	$ (751)	$ 26,752	$ 4,034
OTTI Charges	(2,291)	(1,426)	(3,366)	(5,459)
Net realized gains (losses)	18,134	(2,177)	23,386	(1,425)
Unrealized (losses) recognized in income on equity securities	(20,317)	(2,610)	(8,091)	(15,563)
Net realized and unrealized investment (losses) gains	(2,183)	(4,787)	15,295	(16,988)
Fixed Income Securities [Member]
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on disposals of securities, fixed income securities (excluding OTTI charges)	(1,141)	(9,413)	2,063	(13,922)
Equity Securities [Member]
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on disposals of securities, fixed income securities (excluding OTTI charges)	21,602	8,665	24,733	17,960
Short-Term Investments [Member]
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on disposals of securities, fixed income securities (excluding OTTI charges)	(36)	2	(21)	1
Other Investments [Member]
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on disposals of securities, fixed income securities (excluding OTTI charges)	$ 0	$ (5)	$ (23)	$ (5)

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- Definition

Aggregate net change in unrealized gains or losses on the equity portfolio recognized in net income for the period.

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Amount of unrealized and realized gain (loss) on investment in debt and equity securities.

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

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Amount of realized gain (loss) on investment in marketable security, excluding other-than-temporary impairment (OTTI).

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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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The net realized gains or losses on investments during the period, not including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

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