Transactions with Related Parties (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Number of independent directors			4
Management Agreement initial expiration date			November 5, 2011
Management Agreement additional term of expiration (in years)			1
Proportion of average annual management fee			3
Prior notice for uncertain termination (in days)			180
Period of annual management fees earned (in years)			2
Management fee	$ 3,531,000	$ 2,196,000	$ 6,623,000	$ 4,379,000
Management fee payable	1,171,000		1,171,000		828,000
Minimum [Member] | Company's Equity in Excess of $250 Million and up to $500 Million [Member]
Management fee payable			250,000,000
Minimum [Member] | Company's Equity in Excess of $500 Million and up to $750 Million [Member]
Management fee payable			500,000,000
Minimum [Member] | Company's Equity in Excess of $750 [Member]
Management fee payable			750,000,000
Maximum [Member] | Company's Equity up to $250 Million [Member]
Management fee payable			250,000,000
Maximum [Member] | Company's Equity in Excess of $250 Million and up to $500 Million [Member]
Management fee payable			500,000,000
Maximum [Member] | Company's Equity in Excess of $500 Million and up to $750 Million [Member]
Management fee payable			$ 750,000,000
Company's Equity up to $250 Million [Member]
Management fee bases per annum			1.50%
Company's Equity in Excess of $250 Million and up to $500 Million [Member]
Management fee bases per annum			1.10%
Company's Equity in Excess of $500 Million and up to $750 Million [Member]
Management fee bases per annum			0.80%
Company's Equity in Excess of $750 [Member]
Management fee bases per annum			0.50%