Fair Value (Schedule Of Fair Value Of Predominantly Bank Trust Preferred CDOs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012
Financing Receivable, Recorded Investment [Line Items]
Fair value of predominantly bank trust preferred CDOs	765,465
Percentage of total fair value by vintage	100.00%
AAA [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	72.60%
A [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	27.00%
BBB [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.40%
2001 [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value of predominantly bank trust preferred CDOs	54,703
Percentage of total fair value by vintage	7.10%
2001 [Member] | AAA [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	6.00%
2001 [Member] | A [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	1.00%
2001 [Member] | BBB [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.10%
2002 [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value of predominantly bank trust preferred CDOs	232,448
Percentage of total fair value by vintage	30.40%
2002 [Member] | AAA [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	27.80%
2002 [Member] | A [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	2.60%
2002 [Member] | BBB [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.00%
2003 [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value of predominantly bank trust preferred CDOs	266,372
Percentage of total fair value by vintage	34.80%
2003 [Member] | AAA [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	23.90%
2003 [Member] | A [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	10.90%
2003 [Member] | BBB [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.00%
2004 [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value of predominantly bank trust preferred CDOs	126,927
Percentage of total fair value by vintage	16.60%
2004 [Member] | AAA [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	7.20%
2004 [Member] | A [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	9.40%
2004 [Member] | BBB [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.00%
2005 [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value of predominantly bank trust preferred CDOs	13,121
Percentage of total fair value by vintage	1.80%
2005 [Member] | AAA [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.90%
2005 [Member] | A [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.80%
2005 [Member] | BBB [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.10%
2006 [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value of predominantly bank trust preferred CDOs	39,395
Percentage of total fair value by vintage	5.10%
2006 [Member] | AAA [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	2.60%
2006 [Member] | A [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	2.30%
2006 [Member] | BBB [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.20%
2007 [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value of predominantly bank trust preferred CDOs	32,499
Percentage of total fair value by vintage	4.20%
2007 [Member] | AAA [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	4.20%
2007 [Member] | A [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.00%
2007 [Member] | BBB [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of total fair value	0.00%