Insurance Premiums (Undiscounted Future Amount Of Premiums Expected To Be Collected And Period Which Those Collections Are Expected To Occur) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Insurance Premiums [Abstract]
Three months ended, March 31, 2015, Expected Collection of Premiums	$ 20
Three months ended, June 30, 2015, Expected Collection of Premiums	32
Three months ended, September 30, 2015, Expected Collection of Premiums	21
Three months ended, December 31, 2015, Expected Collection of Premiums	24
Twelve months ended, December 31, 2016, Expected Collection of Premiums	91
Twelve months ended, December 31, 2017, Expected Collection of Premiums	83
Twelve months ended, December 31, 2018, Expected Collection of Premiums	73
Twelve months ended, December 31, 2019, Expected Collection of Premiums	68
Five years ended, December 31, 2024, Expected Collection of Premiums	282
Five years ended, December 31, 2029, Expected Collection of Premiums	204
Five years ended, December 31, 2034 and thereafter, Expected Collection of Premiums	213
Total, Expected Collection of Premiums	$ 1,111