Variable Interest Entities ("VIE's") (CLN Structures' Underlying Collateral By Industry And Rating) (Details)	3 Months Ended
	Mar. 31, 2013
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	100.00%
AAA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.60%
AA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	13.90%
A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	42.20%
BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	35.40%
BB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	6.80%
B
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.80%
CCC
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.30%
Financial Intermediaries [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	10.50%
Financial Intermediaries [Member] | AA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	2.10%
Financial Intermediaries [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	7.00%
Financial Intermediaries [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	1.40%
Telecommunications [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	10.50%
Telecommunications [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	5.50%
Telecommunications [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	4.50%
Telecommunications [Member] | B
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.50%
Oil And Gas [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	8.00%
Oil And Gas [Member] | AAA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.30%
Oil And Gas [Member] | AA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	2.10%
Oil And Gas [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	1.00%
Oil And Gas [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	4.60%
Utilities [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	4.80%
Utilities [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	2.60%
Utilities [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	2.20%
Chemicals And Plastics [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	3.80%
Chemicals And Plastics [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	2.30%
Chemicals And Plastics [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	1.20%
Chemicals And Plastics [Member] | BB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.30%
Drugs [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	3.70%
Drugs [Member] | AAA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.30%
Drugs [Member] | AA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	2.20%
Drugs [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	1.20%
Retailers (Except Food And Drug) [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	3.50%
Retailers (Except Food And Drug) [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	2.10%
Retailers (Except Food And Drug) [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.90%
Retailers (Except Food And Drug) [Member] | BB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.50%
Industrial Equipment [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	3.30%
Industrial Equipment [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	3.00%
Industrial Equipment [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.30%
Sovereign [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	3.20%
Sovereign [Member] | AA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.70%
Sovereign [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	1.20%
Sovereign [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	1.30%
Conglomerates [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	3.20%
Conglomerates [Member] | AA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	2.30%
Conglomerates [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.90%
Forest Products [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	3.00%
Forest Products [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	1.60%
Forest Products [Member] | BB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	1.40%
Other [Member]
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	42.50%
Other [Member] | AA
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	4.50%
Other [Member] | A
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	15.40%
Other [Member] | BBB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	17.40%
Other [Member] | BB
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	4.60%
Other [Member] | B
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.30%
Other [Member] | CCC
Credit Linked Notes By Industry And Ratings [Line Items]
Credit linked note by industry percentage	0.30%