Securities in an Unrealized Loss Position (Non-Investment Grade Fixed Maturity Securities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Aggregate Fair Value	$ 2,895,204	$ 3,441,075
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Aggregate Fair Value	388,661	719,251
Corporate
Schedule of Available-for-sale Securities [Line Items]
Aggregate Fair Value	1,800,866	1,118,447
Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Aggregate Fair Value	2,829,501	3,407,916
Unrealized Loss Less than 5 Million \| Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Number Of Securities	9
Aggregate Fair Value	28,537
Gross Unrealized Loss	1,699
Unrealized Loss Less than 5 Million \| Corporate
Schedule of Available-for-sale Securities [Line Items]
Number Of Securities	10
Aggregate Fair Value	24,528
Gross Unrealized Loss	742
Unrealized Loss Less than 5 Million \| State and Municipal
Schedule of Available-for-sale Securities [Line Items]
Number Of Securities	2
Aggregate Fair Value	11,177
Gross Unrealized Loss	247
Unrealized Loss Less than 5 Million \| Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Number Of Securities	21
Aggregate Fair Value	64,242
Gross Unrealized Loss	$ 2,688

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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- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ 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)

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

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- Definition

Available For Sale Equity Securities Continuous Unrealized Loss Position Aggregate Loss

+ References

No definition available.

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