Bank Loans and Related Allowance for Loan Losses (Credit Quality of Residential Real Estate Mortgages and HELOCs by Reviewing FICO Scores at Origination, Current FICO Scores, Loan-To-Value Ratio) (Details) $ in Millions	Dec. 31, 2015 USD ($) item	Dec. 31, 2014 USD ($) item
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 14,365	$ 13,441
Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 8,334	$ 8,127
Weighted Average Updated FICO | item	773	773
Percent of Loans that are on Nonaccrual Status	0.11%	0.18%
Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 2,735	$ 2,955
Weighted Average Updated FICO | item	770	769
Utilization Rate	39.00%	39.00%
Percent of Loans that are on Nonaccrual Status	0.18%	0.20%
Pledged asset lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 3,232	$ 2,320
Year of origination Pre 2011 [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	882	1,119
Year of origination Pre 2011 [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	1,934	2,244
Year of origination 2011 [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	424	588
Year of origination 2011 [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	114	137
Year of origination 2012 [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	1,644	2,107
Year of origination 2012 [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	125	147
Year of origination 2013 [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	2,450	3,047
Year of origination 2013 [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	232	250
Year of origination 2014 [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	1,021	1,266
Year of origination 2014 [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	188	177
Year of origination 2015 [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	1,913
Year of origination 2015 [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	142
Origination FICO Score Below 620 [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	10	10
Origination FICO Score 620 Through 679 [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	88	97
Origination FICO Score 620 Through 679 [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	16	18
Origination FICO Score 680 Through 739 [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	1,381	1,366
Origination FICO Score 680 Through 739 [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	498	549
Origination FICO Score 740 And Above [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	6,855	6,654
Origination FICO Score 740 And Above [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	2,221	2,388
Origination Loan To Value Ratio 70% And Below [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	5,913	5,572
Origination Loan To Value Ratio 70% And Below [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	1,858	1,979
Origination Loan to Value Ratio Greater Than 70% Through 90% [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	2,408	2,538
Origination Loan to Value Ratio Greater Than 70% Through 90% [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	860	955
Origination Loan to Value Ratio Greater Than 90% Through 100% [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	13	17
Origination Loan to Value Ratio Greater Than 90% Through 100% [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	17	21
Estimated Current LTV 70% And Below [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 7,508	$ 7,131
Weighted Average Updated FICO | item	774	774
Percent of Loans that are on Nonaccrual Status	0.03%	0.04%
Estimated Current LTV 70% And Below [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 2,277	$ 2,282
Weighted Average Updated FICO | item	772	773
Utilization Rate	37.00%	36.00%
Percent of Loans that are on Nonaccrual Status	0.09%	0.08%
Estimated Current LTV Greater Than 70% through 90% [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 759	$ 882
Weighted Average Updated FICO | item	764	765
Percent of Loans that are on Nonaccrual Status	0.31%	0.50%
Estimated Current LTV Greater Than 70% through 90% [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 373	$ 526
Weighted Average Updated FICO | item	760	762
Utilization Rate	50.00%	48.00%
Percent of Loans that are on Nonaccrual Status	0.48%	0.34%
Estimated Current LTV Greater Than 90% through 100% [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 37	$ 61
Weighted Average Updated FICO | item	736	740
Percent of Loans that are on Nonaccrual Status	5.54%	2.95%
Estimated Current LTV Greater Than 90% through 100% [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 48	$ 81
Weighted Average Updated FICO | item	748	749
Utilization Rate	63.00%	61.00%
Percent of Loans that are on Nonaccrual Status	1.02%	1.67%
Estimated Current LTV Greater Than 100% [Member] | Residential real estate mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 30	$ 53
Weighted Average Updated FICO | item	713	726
Percent of Loans that are on Nonaccrual Status	7.72%	10.95%
Estimated Current LTV Greater Than 100% [Member] | Home equity loans and lines of credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 37	$ 66
Weighted Average Updated FICO | item	739	742
Utilization Rate	67.00%	63.00%
Percent of Loans that are on Nonaccrual Status	1.79%	1.54%
Weighted Average Loan to Value Ratio =70% [Member] | Pledged asset lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Bank loans	$ 3,232	$ 2,320
Weighted Average Updated FICO | item	764	764
Utilization Rate	49.00%	50.00%