Schedule V - Reinsurance (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Direct Amount	$ 1,873,007	$ 1,693,021	$ 1,654,301
Assumed From Other Companies	65,884	29,011	26,619
Ceded To Other Companies	354,772	282,719	264,322
Net Amount	1,584,119	1,439,313	1,416,598
% of Amount Assumed To Net	4.00%	2.00%	2.00%
Accident and Health Insurance Segment [Member]
Direct Amount	58	62	67
Assumed From Other Companies	0	0	0
Ceded To Other Companies	58	62	67
Net Amount	0	0	0
% of Amount Assumed To Net	0.00%	0.00%	0.00%
Property and liability insurance [Member]
Direct Amount	1,872,949	1,692,959	1,654,234
Assumed From Other Companies	65,884	29,011	26,619
Ceded To Other Companies	354,714	282,657	264,255
Net Amount	$ 1,584,119	$ 1,439,313	$ 1,416,598
% of Amount Assumed To Net	4.00%	2.00%	2.00%

Amount of premiums assumed from other companies.

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=6588446&loc=d3e574992-122915

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Amount of premiums ceded to other companies.

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Gross amount of premium revenue.

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Net amount of gross premiums, less premiums ceded to other companies, plus premiums assumed from other companies; which represents the net amount of premium revenue on the income statement.

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Percentage of amount of premiums assumed from other companies to net amount of premiums.

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