This element represents expenses related to both deferred policy acquisition costs, amortization expense (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) and other underwriting expenses (costs incurred during the period, such as those relating to general administration and policy maintenance that do not vary with and are not primarily related to the acquisition or renewal of insurance contracts).

No definition available.

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues
Premiums earned									$ 5,344us-gaap_PremiumsEarnedNet	$ 4,898us-gaap_PremiumsEarnedNet	$ 4,493us-gaap_PremiumsEarnedNet
Net investment income									446us-gaap_NetInvestmentIncome	422us-gaap_NetInvestmentIncome	438us-gaap_NetInvestmentIncome
Net realized investment gains (losses)									193us-gaap_RealizedInvestmentGainsLosses	771us-gaap_RealizedInvestmentGainsLosses	418us-gaap_RealizedInvestmentGainsLosses
Net impairment losses recognized in earnings									(4)	(13)	0
Equity in earnings of limited partnerships									113	161	131
Other income									32	32	32
Total revenues	1,589us-gaap_Revenues	1,426us-gaap_Revenues	1,598us-gaap_Revenues	1,511us-gaap_Revenues	1,697us-gaap_Revenues	1,577us-gaap_Revenues	1,426us-gaap_Revenues	1,571us-gaap_Revenues	6,124us-gaap_Revenues	6,271us-gaap_Revenues	5,512us-gaap_Revenues
Benefits and expenses
Insurance losses and loss expenses									3,958	3,467	3,480
Policy acquisition and underwriting expenses									1,336	1,237	1,133
Total benefits and expenses	1,212us-gaap_BenefitsLossesAndExpenses	1,276us-gaap_BenefitsLossesAndExpenses	1,451us-gaap_BenefitsLossesAndExpenses	1,355us-gaap_BenefitsLossesAndExpenses	1,227us-gaap_BenefitsLossesAndExpenses	1,179us-gaap_BenefitsLossesAndExpenses	1,163us-gaap_BenefitsLossesAndExpenses	1,135us-gaap_BenefitsLossesAndExpenses	5,294us-gaap_BenefitsLossesAndExpenses	4,704us-gaap_BenefitsLossesAndExpenses	4,613us-gaap_BenefitsLossesAndExpenses
Income (loss) from operations before income taxes and noncontrolling interest	377	150	147	156	470	398	263	436	830	1,567	899
Provision for income taxes									257us-gaap_IncomeTaxExpenseBenefit	519us-gaap_IncomeTaxExpenseBenefit	280us-gaap_IncomeTaxExpenseBenefit
Net income (loss)	253us-gaap_ProfitLoss	108us-gaap_ProfitLoss	103us-gaap_ProfitLoss	109us-gaap_ProfitLoss	314us-gaap_ProfitLoss	267us-gaap_ProfitLoss	177us-gaap_ProfitLoss	290us-gaap_ProfitLoss	573us-gaap_ProfitLoss	1,048us-gaap_ProfitLoss	619us-gaap_ProfitLoss
Less: Net income (loss) attributable to noncontrolling interest in consolidated entity – Exchange	227	61	54	63	278	221	133	253	405	885	459
Net income (loss) attributable to Indemnity	26us-gaap_NetIncomeLoss	47us-gaap_NetIncomeLoss	49us-gaap_NetIncomeLoss	46us-gaap_NetIncomeLoss	36us-gaap_NetIncomeLoss	46us-gaap_NetIncomeLoss	44us-gaap_NetIncomeLoss	37us-gaap_NetIncomeLoss	168us-gaap_NetIncomeLoss	163us-gaap_NetIncomeLoss	160us-gaap_NetIncomeLoss
Indemnity
Revenues
Net investment income									16	15	16
Net realized investment gains (losses)									1	1	5
Net impairment losses recognized in earnings									0	0	0
Equity in earnings of limited partnerships									11	22	15
Benefits and expenses
Income (loss) from operations before income taxes and noncontrolling interest									251	247	241
Provision for income taxes									83	84	81
Net income (loss) attributable to Indemnity									$ 168	$ 163	$ 160
Class A \| Indemnity
Net income attributable to Indemnity per share
Common stock - basic (in dollars per share)	$ 0.54	$ 1.01	$ 1.05	$ 0.99	$ 0.75	$ 0.98	$ 0.95	$ 0.78	$ 3.59	$ 3.46	$ 3.38
Common stock - diluted (in dollars per share)	$ 0.48	$ 0.90	$ 0.94	$ 0.88	$ 0.67	$ 0.87	$ 0.84	$ 0.69	$ 3.18	$ 3.08	$ 2.99
Weighted average shares outstanding attributable to Indemnity - Basic
Common stock - basic (in shares)									46,247,876	46,660,651	47,357,836
Weighted average shares outstanding attributable to Indemnity - Diluted
Common stock - diluted (in shares)									52,616,234	52,855,757	53,547,833
Class B \| Indemnity
Net income attributable to Indemnity per share
Common stock - basic (in dollars per share)	$ 81	$ 151.00	$ 158.00	$ 149.00	$ 113.00	$ 147.00	$ 142.00	$ 117.00	$ 539.00	$ 520.00	$ 505.00
Common stock - diluted (in dollars per share)	$ 81	$ 151.00	$ 158.00	$ 149.00	$ 113.00	$ 147.00	$ 142.00	$ 117.00	$ 538.00	$ 519.00	$ 505.00
Weighted average shares outstanding attributable to Indemnity - Basic
Common stock - basic (in shares)									2,542	2,542	2,544
Weighted average shares outstanding attributable to Indemnity - Diluted
Common stock - diluted (in shares)									2,542	2,542	2,544