Condensed Consolidated Statement of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Cumulative Distributions in Excess of Net Income [Member]
Balance at Dec. 31, 2010	$ 177,533	$ 251	$ 177,275	$ 7
Balance, Shares at Dec. 31, 2010		25,061,072
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,678			5,678
Amortization of stock based compensation	3,249		3,249
Stock issuance, Value	163,342	118	163,224
Stock issuance, Shares		11,807,176
Common dividends	(19,878)			(19,878)
Balance at Sep. 30, 2011	329,924	369	343,748	(14,193)
Balance, Shares at Sep. 30, 2011		36,868,248
Balance at Dec. 31, 2011	326,573	369	344,995	(18,791)
Balance, Shares at Dec. 31, 2011	36,891,712	36,891,712
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,554			15,554
Amortization of stock based compensation	5,969		5,969
Stock issuance, Value	144	2	142
Stock issuance, Shares		159,530
Common dividends	(36,921)			(36,921)
Balance at Sep. 30, 2012	$ 311,319	$ 371	$ 351,106	$ (40,158)
Balance, Shares at Sep. 30, 2012	37,051,242	37,051,242