Securities In An Unrealized Loss Position Non-Investment Grade Fixed Maturity Securities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	$ 2,215,999	$ 2,895,204
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	64,198	69,142
Common stocks
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	48,645	15,929
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	9,383	5,453
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	301,968	388,661
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	6,753	9,501
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	1,186,059	1,800,866
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	19,776	24,781
State and municipal
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	423,402	308,878
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	4,446	4,020
Foreign government
Schedule of Available-for-sale Securities [Line Items]
Aggregate fair value of securities in a continuous unrealized loss position	100,887	161,496
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses Accumulated In AOCI	18,141	18,065
Noninvestment Grade Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	7
Aggregate fair value of securities in a continuous unrealized loss position	75,300
Noninvestment Grade Investments at Loss Less than 5 Million
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	14
Aggregate fair value of securities in a continuous unrealized loss position	29,133
Gross Unrealized Loss	2,078
Noninvestment Grade Investments at Loss Less than 5 Million \| Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	9
Aggregate fair value of securities in a continuous unrealized loss position	26,168
Gross Unrealized Loss	1,658
Noninvestment Grade Investments at Loss Less than 5 Million \| Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of Securities	5
Aggregate fair value of securities in a continuous unrealized loss position	2,965
Gross Unrealized Loss	$ 420

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (b)(3)

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