Equity Investments - Summarized Statements of Operations of Real Estate Equity Investments (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]
Interest, dividends and discount accretion	$ 18,455,000	$ 21,123,000	$ 25,458,000
Expenses
General and administrative	4,363,000	3,529,000	3,527,000
SoCal [Member]
Schedule of Equity Method Investments [Line Items]
Interest, dividends and discount accretion		25,122,000
Expenses
Interest		7,794,000
General and administrative		424,000
Other expenses		12,000
Total expense		8,230,000
Income from continuing operations		16,892,000
Trust's share of net income		$ 9,706,000