Supplemental Schedule of Reinsurance (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums, Life Insurance in Force	$ 78,000,000us-gaap_LifeInsuranceInForceGross	$ 77,000,000us-gaap_LifeInsuranceInForceGross	$ 76,000,000us-gaap_LifeInsuranceInForceGross
Ceded Premiums, Life Insurance in Force	230,544,000,000us-gaap_LifeInsuranceInForceCeded	36,830,000,000us-gaap_LifeInsuranceInForceCeded	38,048,000,000us-gaap_LifeInsuranceInForceCeded
Assumed Premiums, Life Insurance in Force	2,943,517,000,000us-gaap_LifeInsuranceInForceAssumed	2,889,804,000,000us-gaap_LifeInsuranceInForceAssumed	2,927,573,000,000us-gaap_LifeInsuranceInForceAssumed
Premiums, Net, Life Insurance in Force	2,713,051,000,000us-gaap_LifeInsuranceInForceNet	2,853,051,000,000us-gaap_LifeInsuranceInForceNet	2,889,601,000,000us-gaap_LifeInsuranceInForceNet
Life Insurance in Force Premiums, Percentage Assumed to Net	108.50%	101.30%	101.30%
Direct Premiums Earned	19,365,000us-gaap_DirectPremiumsEarned	5,224,000us-gaap_DirectPremiumsEarned	3,784,000us-gaap_DirectPremiumsEarned
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	447,889,000us-gaap_CededPremiumsEarned	319,419,000us-gaap_CededPremiumsEarned	325,999,000us-gaap_CededPremiumsEarned
Assumed Premiums Earned	9,098,378,000us-gaap_AssumedPremiumsEarned	8,568,222,000us-gaap_AssumedPremiumsEarned	8,228,811,000us-gaap_AssumedPremiumsEarned
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	8,669,854,000us-gaap_PremiumsEarnedNet	8,254,027,000us-gaap_PremiumsEarnedNet	7,906,596,000us-gaap_PremiumsEarnedNet
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	104.90%us-gaap_PremiumsPercentageAssumedToNet	103.80%us-gaap_PremiumsPercentageAssumedToNet	104.10%us-gaap_PremiumsPercentageAssumedToNet
US Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	9,600,000	5,200,000	3,800,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	287,800,000	146,200,000	152,100,000
Assumed Premiums Earned	5,003,700,000	4,704,400,000	4,491,200,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	4,725,500,000	4,563,400,000	4,342,900,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	105.90%	103.10%	103.40%
US Non-Traditional Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	0	0	0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	39,400,000	44,700,000	50,500,000
Assumed Premiums Earned	59,500,000	67,200,000	64,600,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	20,100,000	22,500,000	14,100,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	296.00%	298.70%	458.20%
Canada Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	0	0	0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	49,600,000	54,200,000	52,900,000
Assumed Premiums Earned	1,024,200,000	1,016,500,000	968,600,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	974,600,000	962,300,000	915,700,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	105.10%	105.60%	105.80%
Europe And South Africa Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	9,800,000	0	0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	30,400,000	25,800,000	26,200,000
Assumed Premiums Earned	1,394,600,000	1,246,600,000	1,241,400,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	1,374,000,000	1,220,800,000	1,215,200,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	101.50%	102.10%	102.20%
Asia Pacific Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	0	0	0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	40,700,000	48,500,000	44,300,000
Assumed Premiums Earned	1,615,600,000	1,533,700,000	1,453,800,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	1,574,900,000	1,485,200,000	1,409,500,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	102.60%	103.30%	103.10%
Corporate And Other Segment Reporting Information [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Earned	0	0	0
Reinsurance Premiums for Insurance Companies, by Product Segment, Amount Ceded to Other Companies	0	0	0
Assumed Premiums Earned	800,000	(200,000)	9,200,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Net Amount	$ 800,000	$ (200,000)	$ 9,200,000
Reinsurance Premiums for Insurance Companies, by Product Segment, Percentage of Amount Assumed to Net	100.00%	100.00%	100.00%

Amount of earned premiums assumed from other entities.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

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

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Amount of life insurance issued and outstanding assumed from other entities. Includes, but not limited to, dividends and adjustments to face value.

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Amount before contracts ceded to other entities and contracts assumed by the entity of life insurance issued and outstanding. Includes, but not limited to, dividends and adjustments to face value.

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

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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