Indemnity Earnings Per Share (Details) (Indemnity, USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Class A
Income available to stockholders (Basic EPS:)
Allocated net income (numerator) (in dollars)	$ 47	$ 46	$ 141	$ 126
Weighted shares (denominator) (in shares)	46,189,068	46,656,911	46,267,694	46,707,971
Per-share amount (in dollars per share)	$ 1.01	$ 0.98	$ 3.05	$ 2.71
Dilutive effect of stock-based awards
Allocated net income (numerator) (in dollars)	0	0	0	0
Weighted shares (denominator) (in shares)	97,296	93,539	97,296	93,539
Assumed conversion of Class B shares
Allocated net income (numerator) (in dollars)	0	0	1	1
Weighted shares (denominator) (in shares)	6,100,800	6,100,800	6,100,800	6,100,800
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator) (in dollars)	47	46	142	127
Weighted shares (denominator) (in shares)	52,387,164	52,851,250	52,465,790	52,902,310
Per-share amount (in dollars per share)	$ 0.90	$ 0.87	$ 2.71	$ 2.41
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%
Income available to stockholders (Basic EPS:)
Allocated net income (numerator) (in dollars)	0	0	1	1
Weighted shares (denominator) (in shares)	2,542	2,542	2,542	2,542
Per-share amount (in dollars per share)	$ 151.00	$ 147.00	$ 458.00	$ 406.00
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator) (in dollars)	$ 0	$ 0	$ 1	$ 1
Weighted shares (denominator) (in shares)	2,542	2,542	2,542	2,542
Per-share amount (in dollars per share)	$ 151.00	$ 147.00	$ 457.00	$ 406.00