Description of Trust and Reporting Policies - Additional Information (Detail) (USD $)		1 Months Ended
	Sep. 30, 2014 Liquidation Basis of Accounting [Member]	Oct. 31, 2014 Subsequent Event [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Accrued dividends and interest income	$ 3,600,000
Accrued dividends	3,465,000
Accrued interest income	$ 130,000
Dividends declared per share for accrued dividend		$ 0.30
Accrued dividends record date		Dec. 10, 2014