Financing Receivables (Credit Quality Information Tables) (Details 2) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 3,922	$ 3,993
Less: allowance for loan losses	$ 34	$ 35	$ 33	$ 37
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of commercial mortgage loans with highest risk rating	1.00%	1.00%
Total loans, gross	$ 2,735	$ 2,729
Less: allowance for loan losses	23	25
Total loans, net	$ 2,712	$ 2,704
Percentage of gross commercial mortgage loans	100.00%	100.00%
Commercial Real Estate Portfolio Segment [Member] | Apartment Building [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 500	$ 500
Percentage of gross commercial mortgage loans	18.00%	18.00%
Commercial Real Estate Portfolio Segment [Member] | Hotel [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 38	$ 34
Percentage of gross commercial mortgage loans	1.00%	1.00%
Commercial Real Estate Portfolio Segment [Member] | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 455	$ 461
Percentage of gross commercial mortgage loans	17.00%	17.00%
Commercial Real Estate Portfolio Segment [Member] | Mixed use [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 45	$ 45
Percentage of gross commercial mortgage loans	2.00%	2.00%
Commercial Real Estate Portfolio Segment [Member] | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 540	$ 545
Percentage of gross commercial mortgage loans	20.00%	20.00%
Commercial Real Estate Portfolio Segment [Member] | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 967	$ 988
Percentage of gross commercial mortgage loans	35.00%	36.00%
Commercial Real Estate Portfolio Segment [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 190	$ 156
Percentage of gross commercial mortgage loans	7.00%	6.00%
Commercial Real Estate Portfolio Segment [Member] | East North Central [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 207	$ 238
Percentage of gross commercial mortgage loans	8.00%	9.00%
Commercial Real Estate Portfolio Segment [Member] | East South Central [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 63	$ 62
Percentage of gross commercial mortgage loans	2.00%	2.00%
Commercial Real Estate Portfolio Segment [Member] | Middle Atlantic [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 203	$ 217
Percentage of gross commercial mortgage loans	7.00%	8.00%
Commercial Real Estate Portfolio Segment [Member] | Mountain [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 254	$ 245
Percentage of gross commercial mortgage loans	9.00%	9.00%
Commercial Real Estate Portfolio Segment [Member] | New England [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 131	$ 140
Percentage of gross commercial mortgage loans	5.00%	5.00%
Commercial Real Estate Portfolio Segment [Member] | Pacific [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 743	$ 694
Percentage of gross commercial mortgage loans	27.00%	25.00%
Commercial Real Estate Portfolio Segment [Member] | South Atlantic [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 742	$ 740
Percentage of gross commercial mortgage loans	27.00%	27.00%
Commercial Real Estate Portfolio Segment [Member] | West North Central [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 237	$ 233
Percentage of gross commercial mortgage loans	9.00%	9.00%
Commercial Real Estate Portfolio Segment [Member] | West South Central [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, gross	$ 155	$ 160
Percentage of gross commercial mortgage loans	6.00%	6.00%