Organization and Summary of Significant Accounting Policies (Schedule of Distributions Paid to Shareholders) (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Component Of Operating Cost And Expense [Line Items]
Ordinary income		$ 0.00	$ 0.11
Non-dividend distributions	$ 0.84	0.84	0.69
Distribution paid to shareholders	0.84	0.84	0.80
Series A Preferred Shares[Member]
Component Of Operating Cost And Expense [Line Items]
Ordinary income			2.06
Non-dividend distributions	2.06	2.06
Distribution paid to shareholders	2.06	2.06	2.06
Series B Preferred Shares [Member]
Component Of Operating Cost And Expense [Line Items]
Ordinary income			1.84
Non-dividend distributions	1.84	1.84	0.00
Distribution paid to shareholders	$ 1.84	$ 1.84	$ 1.84