Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended
	Jun. 30, 2014
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Quarterly dividend paid per Common Share	$ 0.1625
Series D Preferred Shares of Beneficial Interest [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Quarterly dividend paid per Series D Preferred Share	$ 0.578125