Segments Pretax Earnings by Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Information by business segment
Net earned premium	$ 600,563us-gaap_PremiumsEarnedNet	$ 562,612us-gaap_PremiumsEarnedNet
Other revenue	75,887hcc_OtherRevenue	86,318hcc_OtherRevenue
Total revenue	676,450us-gaap_Revenues	648,930us-gaap_Revenues
Loss and LAE	365,162	330,746
Other expense	160,460hcc_OtherExpense	163,212hcc_OtherExpense
Total expense	525,622us-gaap_BenefitsLossesAndExpenses	493,958us-gaap_BenefitsLossesAndExpenses
Earnings before income taxes	150,828	154,972
North America Property & Casualty [Member]
Information by business segment
Net earned premium	209,239	201,334
Other revenue	6,102	5,431
Total revenue	215,341	206,765
Loss and LAE	116,436	103,553
Other expense	68,348	57,538
Total expense	184,784	161,091
Earnings before income taxes	30,557	45,674
Accident & Health [Member]
Information by business segment
Net earned premium	254,950	232,143
Other revenue	2,013	1,640
Total revenue	256,963	233,783
Loss and LAE	187,011	170,805
Other expense	38,665	34,573
Total expense	225,676	205,378
Earnings before income taxes	31,287	28,405
International [Member]
Information by business segment
Net earned premium	136,377	128,844
Other revenue	1,008	976
Total revenue	137,385	129,820
Loss and LAE	61,443	56,314
Other expense	47,311	46,475
Total expense	108,754	102,789
Earnings before income taxes	28,631	27,031
Investing [Member]
Information by business segment
Net earned premium	0	0
Other revenue	66,668	77,052
Total revenue	66,668	77,052
Loss and LAE	0	0
Other expense	0	0
Total expense	0	0
Earnings before income taxes	66,668	77,052
Corporate & Other [Member]
Information by business segment
Net earned premium	(3)	291
Other revenue	96	1,219
Total revenue	93	1,510
Loss and LAE	272	74
Other expense	6,136	24,626
Total expense	6,408	24,700
Earnings before income taxes	$ (6,315)	$ (23,190)

Other expense including policy acquisition costs, other operating expenses (used in condensed disclosures).

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Revenue other than premium for condensed disclosures.

+ References

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The total amount of expense recognized during the period for future policy benefits, claims and claims adjustment costs, and for selling, general and administrative costs.

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Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

+ References

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

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Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred.

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Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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