Schedule IV. Reinsurance (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	$ 5,366,061us-gaap_LifeInsuranceInForceGross	$ 5,300,305us-gaap_LifeInsuranceInForceGross	$ 5,206,065us-gaap_LifeInsuranceInForceGross
Ceded to Other Companies	1,130,059us-gaap_LifeInsuranceInForceCeded	1,112,688us-gaap_LifeInsuranceInForceCeded	1,083,410us-gaap_LifeInsuranceInForceCeded
Assumed From Other Companies	0us-gaap_LifeInsuranceInForceAssumed	4us-gaap_LifeInsuranceInForceAssumed	22us-gaap_LifeInsuranceInForceAssumed
Net Amount	4,236,002us-gaap_LifeInsuranceInForceNet	4,187,621us-gaap_LifeInsuranceInForceNet	4,122,677us-gaap_LifeInsuranceInForceNet
Property and Casualty Insurance [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	800,492	726,221	659,989
Ceded to Other Companies	49,818	50,514	47,467
Assumed From Other Companies	16,265	18,485	16,889
Net Amount	766,939	694,192	629,411
Percentage of Amount Assumed to Net Earned	2.12%	2.66%	2.68%
Life Insurance [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	64,350	63,446	68,204
Ceded to Other Companies	2,959	2,792	2,621
Assumed From Other Companies	0	0	0
Net Amount	61,391	60,654	65,583
Percentage of Amount Assumed to Net Earned	0.00%	0.00%	0.00%
Total [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	864,842	789,667	728,193
Ceded to Other Companies	52,777	53,306	50,088
Assumed From Other Companies	16,265	18,485	16,889
Net Amount	$ 828,330	$ 754,846	$ 694,994
Percentage of Amount Assumed to Net Earned	1.96%	2.45%	2.43%

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

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

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

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

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