Loan Product Type and Accompanying Loan Characteristics of Commercial Loans (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014 Contract	Dec. 31, 2013 Contract
Commercial Loans [Line Items]
Interest Rate	0.00%
Commercial Loans Held For Investment
Commercial Loans [Line Items]
Number of Loans	60	50
Total Principal	$ 341,750	$ 353,331
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| Fixed Loans
Commercial Loans [Line Items]
Number of Loans	56	46
Total Principal	300,748	303,986
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| Fixed Loans \| Range 1
Commercial Loans [Line Items]
Loan Balance, minimum	0	0
Loan Balance, maximum	5,000	5,000
Interest Rate, minimum	9.50%	9.75%
Interest Rate, maximum	12.50%	12.50%
Maturity start date	2016-08	2016-08
Maturity end date	2024-12	2024-01
Number of Loans	37	24
Total Principal	102,994	70,597
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| Fixed Loans \| Range 2
Commercial Loans [Line Items]
Loan Balance, minimum	5,001	5,001
Loan Balance, maximum	10,000	10,000
Interest Rate		4.43%
Interest Rate, minimum	4.43%	4.43%
Interest Rate, maximum	11.00%	12.25%
Maturity start date	2015-04	2015-04
Maturity end date	2025-01	2023-06
Number of Loans	14	15
Total Principal	109,551	112,887
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| Fixed Loans \| Range 3
Commercial Loans [Line Items]
Loan Balance, minimum	10,001	10,001
Loan Balance, maximum	15,000	15,000
Interest Rate, minimum	9.50%	9.50%
Interest Rate, maximum	9.50%	10.00%
Maturity start date	2018-01	2015-06
Maturity end date	2021-06	2021-06
Number of Loans	2	3
Total Principal	24,874	35,463
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| Fixed Loans \| Range 4
Commercial Loans [Line Items]
Loan Balance, minimum	15,001	15,001
Loan Balance, maximum	20,000	20,000
Interest Rate, minimum	10.00%	10.50%
Interest Rate, maximum	11.00%	11.00%
Maturity start date	2016-06	2016-06
Maturity end date	2022-06	2022-06
Number of Loans	2	2
Total Principal	37,700	37,700
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| Fixed Loans \| Range 5
Commercial Loans [Line Items]
Loan Balance, minimum	25,001	20,001
Loan Balance, maximum	30,000	25,000
Interest Rate	10.00%	9.50%
Maturity date	2016-10	2014-12
Number of Loans	1	1
Total Principal	25,629	21,500
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| Fixed Loans \| Range 6
Commercial Loans [Line Items]
Loan Balance, minimum		25,001
Loan Balance, maximum		30,000
Interest Rate		10.00%
Maturity date		2016-10
Number of Loans		1
Total Principal		25,839
30-89 Days DQ		0
90+ Days DQ		0
Commercial Loans Held For Investment \| ARM Loans
Commercial Loans [Line Items]
Number of Loans	4	4
Total Principal	41,002	49,345
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| ARM Loans \| Range 1
Commercial Loans [Line Items]
Loan Balance, minimum	5,001	5,001
Loan Balance, maximum	10,000	10,000
Interest Rate, minimum	10.80%	10.80%
Interest Rate, maximum	12.00%	12.00%
Maturity start date	2015-02	2015-02
Maturity end date	2016-10	2016-10
Number of Loans	2	2
Total Principal	15,478	15,497
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| ARM Loans \| Range 2
Commercial Loans [Line Items]
Loan Balance, minimum	10,001	10,001
Loan Balance, maximum	15,000	15,000
Interest Rate		11.20%
Interest Rate, minimum	9.16%
Interest Rate, maximum	11.20%
Maturity date		2014-11
Maturity start date	2014-11
Maturity end date	2016-08
Number of Loans	2	1
Total Principal	25,524	14,598
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held For Investment \| ARM Loans \| Range 3
Commercial Loans [Line Items]
Loan Balance, minimum		15,001
Loan Balance, maximum		20,000
Interest Rate		11.99%
Maturity date		2014-08
Number of Loans		1
Total Principal		19,250
30-89 Days DQ		0
90+ Days DQ		0
Commercial Loans Held For Sale
Commercial Loans [Line Items]
Number of Loans	13
Total Principal	163,000
Commercial Loans Held For Sale \| Fixed Loans
Commercial Loans [Line Items]
Interest Rate, minimum	4.19%	4.79%
Interest Rate, maximum	4.79%	5.52%
Maturity start date	2024-12	2023-12
Maturity end date	2045-01	2024-01
Number of Loans	13	7
Total Principal	162,790	87,650
30-89 Days DQ	0	0
90+ Days DQ	0	0
Commercial Loans Held-for-Investment, at Fair Value
Commercial Loans [Line Items]
Number of Loans	3
Total Principal	68,000
Commercial Loans Held-for-Investment, at Fair Value \| Fixed Loans \| Range 1
Commercial Loans [Line Items]
Loan Balance, minimum	0
Loan Balance, maximum	5,000
Interest Rate, minimum	10.00%
Interest Rate, maximum	10.00%
Maturity start date	2023-12
Maturity end date	2024-04
Number of Loans	3
Total Principal	4,555
30-89 Days DQ	0
90+ Days DQ	0
Commercial Loans Held-for-Investment, at Fair Value \| Fixed Loans \| Range 2
Commercial Loans [Line Items]
Loan Balance, minimum	10,001
Loan Balance, maximum	15,000
Interest Rate, minimum	4.95%
Interest Rate, maximum	4.95%
Maturity date	2024-01
Number of Loans	1
Total Principal	11,399
30-89 Days DQ	0
90+ Days DQ	0
Commercial Loans Held-for-Investment, at Fair Value \| Fixed Loans \| Range 3
Commercial Loans [Line Items]
Loan Balance, minimum	20,001
Loan Balance, maximum	25,000
Interest Rate, minimum	4.83%
Interest Rate, maximum	4.83%
Maturity date	2023-12
Number of Loans	1
Total Principal	22,102
30-89 Days DQ	0
90+ Days DQ	0
Commercial Loans Held-for-Investment, at Fair Value \| Fixed Loans \| Range 4
Commercial Loans [Line Items]
Loan Balance, minimum	25,001
Loan Balance, maximum	30,000
Interest Rate	4.79%
Maturity date	2024-04
Number of Loans	1
Total Principal	29,500
30-89 Days DQ	0
90+ Days DQ	0
Commercial Loans Held-for-Investment, at Fair Value \| Fixed Loans \| Range 5
Commercial Loans [Line Items]
Number of Loans	6
Total Principal	67,556
30-89 Days DQ	0
90+ Days DQ	$ 0

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Amount of principal due on commercial loans that have been delinquent thirty to eighty-nine days as of the balance sheet date.

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Mortgage Loan On Real Estate Maximum Amount

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Mortgage Loan On Real Estate Minimum Amount

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The stated interest rate on the mortgage loan receivable or the weighted average interest rate on a group of loans.

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The highest stated interest rate within the mortgage loans included in the loan grouping.

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The lowest stated interest rate within the mortgage loans included in the loan grouping.

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Indicates the number of mortgages under each classification.

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Amount of principal due on loans that have been delinquent, which may exclude loans having interest delinquent for three months or less, as of the balance sheet date.

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This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

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