Pooled Trust Preferred Securities that Have at Least One Credit Rating Below Investment Grade (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013 Entity
INCAPS Funding I Class B-2 Notes
Schedule of Investments [Line Items]
Lowest credit rating assigned to security	CCC
Number of banks/insurance companies currently performing	19
Actual deferrals and defaults as a percentage of original collateral	9.00%
Expected deferrals and defaults as a percentage of remaining performing collateral	22.00%
Expected recoveries as a percentage of remaining performing collateral
Excess subordination as a percentage of remaining performing collateral	15.00%
INCAPS Funding I Class B-2 Notes | Trust Preferred Securities
Schedule of Investments [Line Items]
Book value	$ 14,964
Fair value	19,977
Unrealized gain	5,013
Alesco Preferred Funding VII Ltd. Class C-1 Notes
Schedule of Investments [Line Items]
Lowest credit rating assigned to security	C
Number of banks/insurance companies currently performing	54
Actual deferrals and defaults as a percentage of original collateral	12.00%
Expected deferrals and defaults as a percentage of remaining performing collateral	25.00%
Expected recoveries as a percentage of remaining performing collateral
Alesco Preferred Funding VII Ltd. Class C-1 Notes | Trust Preferred Securities
Schedule of Investments [Line Items]
Book value	553
Fair value	1,005
Unrealized gain	452
Preferred Term Securities II Mezzanine Notes
Schedule of Investments [Line Items]
Lowest credit rating assigned to security	C
Number of banks/insurance companies currently performing	10
Actual deferrals and defaults as a percentage of original collateral	26.00%
Expected deferrals and defaults as a percentage of remaining performing collateral	46.00%
Expected recoveries as a percentage of remaining performing collateral
Preferred Term Securities II Mezzanine Notes | Trust Preferred Securities
Schedule of Investments [Line Items]
Book value	407
Fair value	953
Unrealized gain	$ 546