Indemnity Supplemental Information (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed financial statements
Service agreement fee received	$ 31	$ 33	$ 34
Premiums collected	4,594	4,276	4,055
Net investment income received	471	458	445
Limited partnership distributions	164	166	122
Commissions and bonuses paid to agents	(617)	(583)	(532)
Losses paid	(2,818)	(2,953)	(2,398)
Loss expenses paid	(464)	(439)	(419)
Other underwriting and acquisition costs paid	(557)	(531)	(517)
Income taxes paid	(227)	(67)	(69)
Net cash provided by operating activities	577	360	721
Net cash provided by (used in) investing activities	(85)	(375)	(405)
Net cash used in financing activities	(277)	(230)	(120)
Net increase (decrease) in cash and cash equivalents	215	(245)	196
Cash and cash equivalents at beginning of year	185	430	234
Cash and cash equivalents at end of year	400	185	430
Indemnity
Condensed financial statements
Management fee received	1,135	1,053	947
Service agreement fee received	31	33	34
Premiums collected			220
Net investment income received	28	22	45
Limited partnership distributions	21	22	21
Decrease in reimbursements collected from affiliates	(4)	(9)	(15)
Commissions and bonuses paid to agents	(617)	(583)	(532)
Salaries and wages paid	(130)	(124)	(106)
Pension contribution and employee benefits paid	(38)	(36)	(33)
Losses paid			(132)
Loss expenses paid			(23)
Other underwriting and acquisition costs paid			(53)
General operating expenses paid	(139)	(127)	(119)
Income taxes paid	(82)	(82)	(61)
Net cash provided by operating activities	205	169	193
Net cash provided by (used in) investing activities	95	(211)	196
Net cash used in financing activities	(299)	(257)	(155)
Net increase (decrease) in cash and cash equivalents	1	(299)	234
Cash and cash equivalents at beginning of year	11	310	76
Cash and cash equivalents at end of year	$ 12	$ 11	$ 310