CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Revenues
Premiums earned	$ 1,137	$ 1,061	$ 3,333	$ 3,138
Net investment income	105	108	326	326
Net realized investment gains (losses)	169	(422)	358	(234)
Net impairment losses recognized in earnings	0	0	0	0
Equity in earnings of limited partnerships	41	40	99	150
Other income	8	9	24	26
Total revenues	1,460	796	4,140	3,406
Benefits and expenses
Insurance losses and loss expenses	912	848	2,571	2,724
Policy acquisition and underwriting expenses	278	253	835	749
Total benefits and expenses	1,190	1,101	3,406	3,473
Income (loss) from operations before income taxes and noncontrolling interest	270	(305)	734	(67)
Provision for income taxes	86	(125)	234	(54)
Net income (loss)	184	(180)	500	(13)	268
Less: Net income (loss) attributable to noncontrolling interest in consolidated entity - Exchange	133	(227)	370	(156)
Net income attributable to Indemnity	51	47	130	143
Indemnity
Revenues
Net investment income	4	4	12	12
Net realized investment gains (losses)	2	(6)	4	1
Benefits and expenses
Income (loss) from operations before income taxes and noncontrolling interest	78	67	197	215
Provision for income taxes	27	20	67	72
Net income (loss)			130		169
Net income attributable to Indemnity	$ 51	$ 47	$ 130	$ 143
Class A | Indemnity
Net income attributable to Indemnity per share
Common stock - basic (in dollars per share)	$ 1.08	$ 0.97	$ 2.73	$ 2.90
Common stock - diluted (in dollars per share)	$ 0.96	$ 0.87	$ 2.43	$ 2.59
Weighted average shares outstanding attributable to Indemnity - Basic
Common stock - basic (in shares)	47,188,741	48,503,383	47,476,693	49,176,124
Weighted average shares outstanding attributable to Indemnity - Diluted
Common stock - diluted (in shares)	53,374,846	54,685,021	53,662,798	55,357,762
Dividends declared per share
Common stock (in dollars per share)	$ 0.5525	$ 0.515	$ 1.6575	$ 1.545	$ 2.0975
Class B | Indemnity
Net income attributable to Indemnity per share
Common stock - basic (in dollars per share)	$ 162.02	$ 146.67	$ 410.89	$ 439.39
Common stock - diluted (in dollars per share)	$ 162.02	$ 146.67	$ 410.89	$ 439.39
Weighted average shares outstanding attributable to Indemnity - Basic
Common stock - basic (in shares)	2,544	2,546	2,544	2,546
Weighted average shares outstanding attributable to Indemnity - Diluted
Common stock - diluted (in shares)	2,544	2,546	2,544	2,546
Dividends declared per share
Common stock (in dollars per share)	$ 82.8750	$ 77.250	$ 249	$ 232	$ 315