Indemnity Capital Stock (Details 2) (Indemnity, Class A, Stock repurchase program, USD $) In Millions, unless otherwise specified	1 Months Ended	9 Months Ended
Oct. 31, 2011	Sep. 30, 2012
Indemnity \| Class A \| Stock repurchase program
Stock repurchases
Amount of authorized stock repurchase approved for continuation	$ 150
Approximate amount of repurchase authority remaining under stock repurchase program		$ 84

The remaining repurchase amount authorized by an entity's Board of Directors under a stock repurchase plan.

No definition available.

Name:	us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration