Reinsurance (Details) (USD $) In Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Effect of reinsurance transactions on our premium, loss and loss adjustment expense and policy acquisition costs
Direct written premium	$ 661,301	$ 622,445	$ 1,169,442	$ 1,131,637
Reinsurance assumed	80,781	69,133	221,848	182,437
Reinsurance ceded	(132,209)	(144,776)	(242,533)	(269,021)
Net written premium	609,873	546,802	1,148,757	1,045,053
Direct earned premium	578,703	567,074	1,153,511	1,139,036
Reinsurance assumed	79,113	71,908	158,494	141,148
Reinsurance ceded	(133,565)	(132,597)	(279,274)	(264,212)
Net earned premium	524,251	506,385	1,032,731	1,015,972
Direct loss and loss adjustment expense	343,898	357,918	786,652	718,869
Reinsurance assumed	68,298	52,954	142,205	105,789
Reinsurance ceded	(77,914)	(111,886)	(246,989)	(199,151)
Net loss and loss adjustment expense	334,282	298,986	681,868	625,507
Policy acquisition costs	112,489	109,853	223,847	218,958
Ceding commissions	(28,006)	(28,221)	(55,986)	(57,628)
Net policy acquisition costs	$ 84,483	$ 81,632	$ 167,861	$ 161,330

Assumed loss and loss adjustment expense.

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Ceded loss and loss adjustment expense.

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Ceding commissions.

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Direct earned premium.

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Effect of reinsurance transactions premium, loss and loss adjustment expense and policy acquisition costs

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Policy acquisition costs.

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Reinsurance assumed.

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Reinsurance ceded.

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Premiums for all insurance assumed from other insurers, that is premiums ceded to the entity by other insurers.

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Total consideration paid and payable to reinsurers during the period pursuant to terms of reinsurance arrangements.

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Amount of deferred policy acquisition costs charged to expense in the period, generally in proportion to related revenue earned, estimated gross profits, or over the customer relationship or some other period.

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Total consideration paid and payable by direct policyholders for insurance contracts sold by the Entity during the period. This amount does not include premium assumed from or ceded to other insurers.

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Total provision in the period for future policy benefits, claims incurred and costs incurred in the claims settlement process before the effects of reinsurance arrangements.

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Provision for benefits, claims and claims settlement expenses incurred during the period net of the effects of contracts assumed and ceded.

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Premiums earned on the income statement for all insurance and reinsurance contracts after subtracting any amounts ceded to another insurer and adding premiums assumed from other insurers.

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Premiums written for all insurance and reinsurance contracts, after adding premiums assumed from other insurers and subtracting any amounts ceded to another insurer.

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