Equity Investments - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended	7 Months Ended	9 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended	2 Months Ended	3 Months Ended	8 Months Ended	9 Months Ended	1 Months Ended	3 Months Ended	7 Months Ended	9 Months Ended
	Jul. 31, 2014 CDH CDO LLC [Member]	Sep. 30, 2013 CDH CDO LLC [Member]	Jul. 31, 2014 CDH CDO LLC [Member]	Sep. 30, 2013 CDH CDO LLC [Member]	Jul. 31, 2014 WRT One South State Lender LP [Member]	Aug. 31, 2013 WRT One South State Lender LP [Member]	Jul. 31, 2014 WRT One South State Lender LP [Member]	Aug. 31, 2013 WRT One South State Lender LP [Member]	Jul. 31, 2014 Vintage Housing Holdings [Member]	Aug. 31, 2013 Vintage Housing Holdings [Member]	Jul. 31, 2014 Vintage Housing Holdings [Member]	Aug. 31, 2013 Vintage Housing Holdings [Member]	Jul. 31, 2014 701 7th WRT Investors LLC [Member]	Sep. 30, 2013 701 7th WRT Investors LLC [Member]	Jul. 31, 2014 701 7th WRT Investors LLC [Member]	Sep. 30, 2013 701 7th WRT Investors LLC [Member]
Schedule of Equity Method Investments [Line Items]
Revenues	$ 1,003,000	$ 4,940,000	$ 8,605,000	$ 15,011,000	$ 1,675,000	$ 2,138,000	$ 6,674,000	$ 6,074,000	$ 8,569,000	$ 11,048,000	$ 32,594,000	$ 32,451,000	$ 0	$ 0	$ 0	$ 0
Net income (loss)	$ 318,000	$ 18,145,000	$ (5,485,000)	$ 27,182,000	$ 1,675,000	$ 2,105,000	$ 6,674,000	$ 5,975,000	$ 2,368,000	$ 3,887,000	$ 7,725,000	$ 11,309,000	$ 0	$ 0	$ 0	$ 0