Basis of Presentation and Accounting Policies (details) - Acquisitions (The Dominion of Canada General Insurance Company [Member]) In Millions, unless otherwise specified	Sep. 30, 2013 US Dollars [Member] USD ($)	Sep. 30, 2013 Canadian Dollars [Member] CAD	Jun. 10, 2013 Canadian Dollars [Member] CAD
Business acquisitions
Approximate cash purchase price in agreement to acquire all of the issued and outstanding shares of a foreign entity, subject to adjustment upon final closing of transaction	$ 1,092	1,125	1,125