CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues
Premiums earned									$ 4,898	$ 4,493	$ 4,214
Net investment income									422	438	433
Net realized investment gains (losses)									771	418	(4)
Net impairment losses recognized in earnings									(13)	0	(2)
Equity in earnings of limited partnerships									161	131	149
Other income									32	32	34
Total revenues	1,697	1,577	1,426	1,571	1,372	1,460	1,160	1,520	6,271	5,512	4,824
Benefits and expenses
Insurance losses and loss expenses									3,467	3,480	3,444
Policy acquisition and underwriting expenses									1,237	1,133	1,022
Total benefits and expenses	1,227	1,179	1,163	1,135	1,207	1,190	1,230	986	4,704	4,613	4,466
Income (loss) from operations before income taxes and noncontrolling interest	470	398	263	436	165	270	(70)	534	1,567	899	358
Provision for income taxes									519	280	90
Net income (loss)	314	267	177	290	119	184	(38)	354	1,048	619	268
Less: Net income (loss) attributable to noncontrolling interest in consolidated entity – Exchange	278	221	133	253	89	133	(81)	318	885	459	99
Net income (loss) attributable to Indemnity	36	46	44	37	30	51	43	36	163	160	169
Indemnity
Revenues
Net investment income									15	16	16
Net realized investment gains (losses)									1	5	3
Net impairment losses recognized in earnings									0	0	0
Equity in earnings of limited partnerships									22	15	26
Benefits and expenses
Income (loss) from operations before income taxes and noncontrolling interest									247	241	256
Provision for income taxes									84	81	85
Net income (loss) attributable to Indemnity									$ 163	$ 160	$ 169
Class A | Indemnity
Net income attributable to Indemnity per share
Common stock - basic (in dollars per share)	$ 0.75	$ 0.98	$ 0.95	$ 0.78	$ 0.63	$ 1.08	$ 0.90	$ 0.76	$ 3.46	$ 3.38	$ 3.45
Common stock - diluted (in dollars per share)	$ 0.67	$ 0.87	$ 0.84	$ 0.69	$ 0.56	$ 0.96	$ 0.80	$ 0.67	$ 3.08	$ 2.99	$ 3.08
Weighted average shares outstanding attributable to Indemnity - Basic
Common stock - basic (in shares)									46,660,651	47,357,836	48,875,316
Weighted average shares outstanding attributable to Indemnity - Diluted
Common stock - diluted (in shares)									52,855,757	53,547,833	55,057,437
Class B | Indemnity
Net income attributable to Indemnity per share
Common stock - basic (in dollars per share)	$ 113.00	$ 147.00	$ 142.00	$ 117.00	$ 94	$ 162.00	$ 135.00	$ 114.00	$ 520.00	$ 505.00	$ 522.00
Common stock - diluted (in dollars per share)	$ 113.00	$ 147.00	$ 142.00	$ 117.00	$ 94	$ 162.00	$ 135.00	$ 114.00	$ 519.00	$ 505.00	$ 522.00
Weighted average shares outstanding attributable to Indemnity - Basic
Common stock - basic (in shares)									2,542	2,544	2,546
Weighted average shares outstanding attributable to Indemnity - Diluted
Common stock - diluted (in shares)									2,542	2,544	2,546