Insurance Premiums (Undiscounted Future Amount Of Premiums Expected To Be Collected And The Period Which Those Collections Are Expected To Occur) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Insurance Premiums [Abstract]
Three months ended, March 31, 2012, Expected Collection of Premiums	$ 38
Three months ended, June 30, 2012, Expected Collection of Premiums	57
Three months ended, September 30, 2012, Expected Collection of Premiums	34
Three months ended, December 31, 2012, Expected Collection of Premiums	43
Twelve months ended, December 31, 2013, Expected Collection of Premiums	146
Twelve months ended, December 31, 2014, Expected Collection of Premiums	129
Twelve months ended, December 31, 2015, Expected Collection of Premiums	120
Twelve months ended, December 31, 2016, Expected Collection of Premiums	111
Five years ended, December 31, 2021, Expected Collection of Premiums	419
Five years ended, December 31, 2026, Expected Collection of Premiums	283
Five years ended, December 31, 2031 and thereafter, Expected Collection of Premiums	351
Total, Expected Collection of Premiums	$ 1,731