Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Composition of deferred tax assets and liabilities
Excess of financial statement unearned premium over tax	$ 30,225	$ 26,821
Discounting of loss reserves, net of salvage and subrogation	40,046	50,481
Excess of financial statement accrued expenses over tax	20,103	18,920
Allowance for bad debts, not deductible for tax	2,427	3,146
Stock-based compensation expense in excess of deduction for tax	8,919	5,163
Financial statement loss for Lloyd's syndicates in excess of deduction for tax	0	351
Federal tax net operating loss carryforwards	2,983	3,202
State tax net operating loss carryforwards	441	181
Foreign tax net operating loss carryforwards	20,008	22,605
Federal benefit of state uncertain tax positions	1,705hcc_OtherItems	1,482hcc_OtherItems
Valuation allowance	25,050	27,430
Total deferred tax assets	101,807us-gaap_DeferredTaxAssetsNet	104,922us-gaap_DeferredTaxAssetsNet
Unrealized gain on increase in value of securities	91,515	52,424
Deferred policy acquisition costs, net of ceding commissions, deductible for tax	15,764	14,570
Amortizable goodwill for tax	123,017	110,064
Financial statement income for Lloyd's syndicates in excess of taxable income	7,143	0
Book Basis in net assets of foreign subsidiaries in excess of tax basis	23,075	2,414
Depreciation and other items	12,676	14,458
Total deferred tax liabilities	273,190us-gaap_DeferredTaxLiabilities	193,930us-gaap_DeferredTaxLiabilities
Net deferred tax liability	$ 171,383us-gaap_DeferredTaxAssetsLiabilitiesNet	$ 89,008us-gaap_DeferredTaxAssetsLiabilitiesNet

An excess of the amount for financial reporting over the tax basis of an investment in a foreign subsidiary.

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from reserves and accruals.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the unearned premiums reserve.

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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