Summary of Carrying Value Components of Collateral for ABS Issued and Outstanding (Detail) (Asset-backed Securities, USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	$ 4,010,362	$ 3,935,289
Sequoia
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	3,671,717	3,562,995
Sequoia | REO
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	9,678	14,241
Sequoia | Real Estate Loan
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	3,654,932	3,542,159
Sequoia | Restricted Cash and Cash Equivalents, Cash and Cash Equivalents
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	283	331
Sequoia | Interest Receivable
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	6,824	6,264
Acacia
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	338,645	372,294
Acacia | Real Estate Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	293,308	327,919
Acacia | Real Estate Loan
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	12,698	19,850
Acacia | Restricted Cash and Cash Equivalents, Cash and Cash Equivalents
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	30,287	21,790
Acacia | Interest Receivable
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	2,352	2,735
Real Estate Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	293,308	327,919
REO
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	9,678	14,241
Real Estate Loan
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	3,667,630	3,562,009
Restricted Cash and Cash Equivalents, Cash and Cash Equivalents
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	30,570	22,121
Interest Receivable
Financial Instruments Owned and Pledged as Collateral [Line Items]
Collateral for ABS Issued	$ 9,176	$ 8,999