Indemnity Shareholders' Equity and Noncontrolling Interest (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Reconciliation of the beginning and ending balances of Indemnity's shareholders' equity and the noncontrolling interest
Balance, beginning of period			$ 7,550	$ 6,791	$ 6,791
Net income	103	177	212	467	1,048
Change in other comprehensive income (loss), net of tax	65	(197)	137	(219)	(144)
Net purchase of treasury stock			(19)		(32)
Dividends declared:
Balance, end of period	7,821		7,821		7,550
Class A
Dividends declared:
Dividends declared			(59)		(112)
Class B
Dividends declared:
Dividends declared			0		(1)
Indemnity
Reconciliation of the beginning and ending balances of Indemnity's shareholders' equity and the noncontrolling interest
Balance, beginning of period			734	642	642
Net income			95		163
Change in other comprehensive income (loss), net of tax			4		74
Net purchase of treasury stock			(19)		(32)
Dividends declared:
Balance, end of period	755		755		734
Indemnity | Class A
Dividends declared:
Dividends declared (in dollars per share)	$ 0.6350	$ 0.5925	$ 1.2700	$ 1.1850	$ 2.4125
Dividends declared			(59)		(112)
Indemnity | Class B
Dividends declared:
Dividends declared (in dollars per share)	$ 95.2500	$ 88.8750	$ 190.5000	$ 177.7500	$ 361.8750
Dividends declared			0		(1)
Exchange
Reconciliation of the beginning and ending balances of Indemnity's shareholders' equity and the noncontrolling interest
Balance, beginning of period			6,816	6,149	6,149
Net income			117		885
Change in other comprehensive income (loss), net of tax			133		(218)
Dividends declared:
Balance, end of period	$ 7,066		$ 7,066		$ 6,816