Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on Non-Recurring Basis (Detail) - Jun. 30, 2015 - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Total	Total
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Residential loans, at lower of cost or fair value	$ 1,102	$ 1,102
REO	1,017	1,017
Level 3
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Residential loans, at lower of cost or fair value	1,102	1,102
REO	1,017	1,017
Residential Loans at Lower of Cost or Fair Value
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Gain (Loss) on assets measured at fair value on a non-recurring basis	1	1
REO
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Gain (Loss) on assets measured at fair value on a non-recurring basis	$ (170)	$ (175)