Indemnity Earnings Per Share (Details) (Indemnity, 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
Class A
Income available to stockholders (Basic EPS:)
Allocated net income (numerator) (in dollars)									$ 162	$ 159	$ 168
Weighted shares (denominator) (in shares)									46,660,651	47,357,836	48,875,316
Per-share amount (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
Dilutive effect of stock-based awards
Allocated net income (numerator) (in dollars)									0	0	0
Weighted shares (denominator) (in shares)									94,306	84,397	71,721
Assumed conversion of Class B shares
Allocated net income (numerator) (in dollars)									1	1	1
Weighted shares (denominator) (in shares)									6,100,800	6,105,600	6,110,400
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator) (in dollars)									163	160	169
Weighted shares (denominator) (in shares)									52,855,757	53,547,833	55,057,437
Per-share amount (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
Class B
Reconciliation of the numerators and denominators used in the basic and diluted per-share computations
Ratio for converting shares of Class B common stock into shares of Class A common stock (as a percent)	2400.00%				2400.00%				2400.00%	2400.00%
Income available to stockholders (Basic EPS:)
Allocated net income (numerator) (in dollars)									1	1	1
Weighted shares (denominator) (in shares)									2,542	2,544	2,546
Per-share amount (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
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator) (in dollars)									$ 1	$ 1	$ 1
Weighted shares (denominator) (in shares)									2,542	2,544	2,546
Per-share amount (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