Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)			3 Months Ended	9 Months Ended
	Jun. 16, 2015	Jan. 15, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 15, 2015
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Liquidation distribution per share	$ 1.25	$ 2.25		$ 15.17
Liquidation preference plus accrued and unpaid dividends					$ 25.00
Dividend paid			$ 0
Series D Preferred Shares of Beneficial Interest [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Liquidating distribution per preferred share					$ 25.4815