Realized and Unrealized Investment Gains (Losses) (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	$ 68,282	$ 156,585	$ 58,711	$ 270,975
Income tax expense	(24,713)	(51,552)	(23,973)	(89,087)
Noncontrolling interests	(5)	(5)	14	9
Total change in unrealized gains	43,564	105,028	34,752	181,897
Debt securities
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	56,857	122,893	94,841	215,321
Previously impaired fixed maturity securities
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	743	1,874	844	1,819
Equity securities available for sale
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	6,176	27,814	(42,686)	40,950
Investment funds
Realized and Unrealized Investment Gains Losses [Line Items]
Total change in unrealized investment gains	$ 4,506	$ 4,004	$ 5,712	$ 12,885

This item represents the pretax change in net unrealized holding gain (loss) on available-for-sale securities that has been included in accumulated other comprehensive income, a separate component of shareholders' equity, during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27357-111563

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