Indemnity Supplemental Information (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Condensed financial statements
Service agreement fee received	$ 33	$ 34	$ 35
Premiums collected	4,276	4,055	3,964
Net investment income received	458	445	421
Limited partnership distributions	166	122	81
Commissions and bonuses paid to agents	(583)	(532)	(535)
Losses paid	(2,953)	(2,398)	(2,241)
Loss expenses paid	(439)	(419)	(405)
Other underwriting and acquisition costs paid	(531)	(517)	(552)
Income taxes paid	(67)	(69)	121
Net cash provided by operating activities	360	721	889
Net cash (used in) provided by investing activities	(375)	(405)	(890)
Net cash used in financing activities	(230)	(120)	(42)
Net (decrease) increase in cash and cash equivalents	(245)	196	(43)
Cash and cash equivalents at beginning of year	430	234	277
Cash and cash equivalents at end of year	185	430	234
Indemnity
Condensed financial statements
Management fee received	1,053	947	912
Service agreement fee received	33	34	35
Premiums collected		220	214
Net investment income received	22	45	45
Limited partnership distributions	22	21	13
(Decrease) increase in reimbursements collected from affiliates	(9)	(15)	3
Commissions and bonuses paid to agents	(583)	(532)	(535)
Salaries and wages paid	(124)	(106)	(110)
Pension contribution and employee benefits paid	(36)	(33)	(32)
Losses paid		(132)	(123)
Loss expenses paid		(23)	(22)
Other underwriting and acquisition costs paid		(53)	(54)
General operating expenses paid	(127)	(119)	(104)
Income taxes paid	(82)	(61)	(62)
Net cash provided by operating activities	169	193	180
Net cash (used in) provided by investing activities	(211)	196	(69)
Net cash used in financing activities	(257)	(155)	(96)
Net (decrease) increase in cash and cash equivalents	(299)	234	15
Cash and cash equivalents at beginning of year	310	76	61
Cash and cash equivalents at end of year	$ 11	$ 310	$ 76