Investment Income And Gains And Losses (Significant Inputs Used In Schedule Of Measurement Of Credit Loss Component Recognized In Earnings For Each Significant Class Of ABS) (Details)	6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010
Expected size of losses, Weighted average	67.10%	[1],[2]	64.68%	[1],[2]
Current subordination levels, Weighted average	0.29%	[1],[3]	5.91%	[1],[3]
Prepayment speed (annual CPR), Weighted average	19.40	[1],[4]	9.83	[1],[4]
Minimum Range [Member]
Expected size of losses, Range	0.00%	[2],[5]	0.31%	[2],[5]
Current subordination levels, Range	0.00%	[3],[5]	0.00%	[3],[5]
Prepayment speed (annual CPR), Range	0.00	[4],[5]	0.00	[4],[5]
Maximum Range [Member]
Expected size of losses, Range	100.00%	[2],[5]	100.00%	[2],[5]
Current subordination levels, Range	14.19%	[3],[5]	42.16%	[3],[5]
Prepayment speed (annual CPR), Range	100.00	[4],[5]	51.77	[4],[5]

[1] Calculated by weighting the relevant input/assumption for each individual security by the outstanding notional of the security.

[2] Represents future expected credit losses on impaired assets expressed as a percentage of total outstanding balance.

[3] Represents current level of credit protection (subordination) for the securities, expressed as a percentage of the balance of the collateral group backing the bond.

[4] Values represent high and low points of lifetime vectors of constant prepayment rates.

[5] Represents the range of inputs/assumptions based upon the individual securities within each category.