CONSOLIDATED STATEMENTS OF FINANCIAL POSITION (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Cash and cash equivalents	$ 379	$ 452
Other assets	485	451
Indemnity
Fixed maturities, amortized cost	490	518
Equity securities, cost	35	50
Limited partnerships, cost	119	123
Cash and cash equivalents	44	49
Other assets	113	114
Treasury stock (in shares)	21,995,974	21,838,075
Exchange
Fixed maturities, amortized cost	7,923	7,801
Equity securities, cost	793	778
Trading securities, cost	2,273	2,198
Limited partnerships, cost	780	790
Cash and cash equivalents	335	403
Other assets	$ 372	$ 337
Class A | Indemnity
Common stock, stated value per share (in dollars per share)	$ 0.0292	$ 0.0292
Common stock, authorized (in shares)	74,996,930	74,996,930
Common stock, issued (in shares)	68,299,200	68,299,200
Common stock, outstanding (in shares)	46,303,226	46,461,125
Class B | Indemnity
Ratio for converting shares of Class B common stock into shares of Class A common stock (as a percent)	2400.00%	2400.00%
Common stock, stated value per share (in dollars per share)	$ 70	$ 70
Common stock, authorized (in shares)	3,070	3,070
Common stock, issued (in shares)	2,542	2,542
Common stock, outstanding (in shares)	2,542	2,542