Business Segments Additional Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended	3 Months Ended	9 Months Ended
	Dec. 31, 2014 segment	Dec. 31, 2012	Sep. 30, 2012
Segment Reporting [Abstract]
Number of Reportable Segments	4
Financing Receivable, Impaired [Line Items]
Financing Receivable Collectively Evaluated for Impairment, Difference in Estimate Between US GAAP and Group Reporting Basis	$ 174
Real Estated Loans Accounted Under IFRS [Member]
Financing Receivable, Impaired [Line Items]
Threshold period		10 months	7 months