Schedule IV - Mortgage Loans on Real Estate (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013
Mortgage Loans on Real Estate [Line Items]
Face Value	$ 142,631,000
Outstanding Principal	125,770,000
Carrying Amount	101,100,000
Whole Loan [Member] | New York, NY [Member]
Mortgage Loans on Real Estate [Line Items]
Location	New York, NY
Contractual Maturity Date	Oct. 05, 2014
Periodic Payment Terms	Interest Only
Senior Liens
Face Value	20,000,000
Outstanding Principal	20,000,000
Carrying Amount	20,101,000
Loan bearing interest, terms	LIBOR + 4.0%
Whole Loan [Member] | Tempe [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Tempe, AZ
Contractual Maturity Date	Jan. 01, 2015
Periodic Payment Terms	Amortizing
Senior Liens
Face Value	29,035,000
Outstanding Principal	28,403,000
Carrying Amount	28,547,000
Interest of loan	5.88%
Whole Loan [Member] | Philadelphia [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Philadelphia, PA
Contractual Maturity Date	Feb. 01, 2016
Periodic Payment Terms	Interest Only
Senior Liens	42,440,000
Face Value	36,171,000
Outstanding Principal	24,821,000
Carrying Amount
Interest of loan	7.70%
Whole Loan [Member] | Various / Florida [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Various
Contractual Maturity Date	. NaN, NaN
Periodic Payment Terms	Interest Only
Senior Liens
Face Value	6,088,000
Outstanding Principal	6,088,000
Carrying Amount	6,136,000
Loan bearing interest, terms	Various
Maturity	Various
B Note [Member] | New York, NY [Member]
Mortgage Loans on Real Estate [Line Items]
Location	New York, NY
Contractual Maturity Date	Jul. 11, 2016
Periodic Payment Terms	Amortizing
Senior Liens	243,370,000
Face Value	10,871,000
Outstanding Principal	10,205,000
Carrying Amount	10,250,000
Interest of loan	7.19%
B-Note Other [Member] | Various / Florida [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Various
Contractual Maturity Date	. NaN, NaN
Periodic Payment Terms	Amortizing
Senior Liens	218,366,000
Face Value	15,478,000
Outstanding Principal	12,927,000
Carrying Amount	12,997,000
Loan bearing interest, terms	Various
Maturity	Various
Mezzanine Other [Member]
Mortgage Loans on Real Estate [Line Items]
Face Value	1,486,000
Outstanding Principal	348,000
Mezzanine Other [Member] | Various / Florida [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Various
Contractual Maturity Date	. NaN, NaN
Periodic Payment Terms	Interest Only
Senior Liens	38,883,000
Face Value	4,988,000
Outstanding Principal	3,326,000
Carrying Amount	2,992,000
Loan bearing interest, terms	Various
Maturity	Various
Mezzanine [Member] | Playa Vista / Water's Edge [Member]
Mortgage Loans on Real Estate [Line Items]
Location	Playa Vista, CA
Contractual Maturity Date	Jan. 23, 2015
Periodic Payment Terms	Interest Only
Senior Liens	80,300,000
Face Value	10,250,000
Outstanding Principal	10,250,000
Carrying Amount	10,327,000
Loan bearing interest, terms	LIBOR 4.25%
Corporate Loan [Member]
Mortgage Loans on Real Estate [Line Items]
Location	n/a
Contractual Maturity Date	Oct. 31, 2014
Periodic Payment Terms	Interest Only
Senior Liens
Face Value	9,750,000
Outstanding Principal	9,750,000
Carrying Amount	$ 9,750,000
Interest of loan	15.00%