Consolidated Statements of Equity (USD $) In Thousands, except Share data	Common stock	Additional Paid-in Capital	Distributions in Excess of Accumulated Earnings	Total Stockholders' Equity	Noncontrolling Interests in Operating Partnerships	Total Equity
Balance at Dec. 30, 2008	$ 20	$ 154,412	$ (20,014)	$ 134,418	$ 497,485	$ 631,903
Balance (in shares) at Dec. 30, 2008	19,748,211
Net income			8,391	8,391	26,058	34,449
Dividends declared per common share and O.P. Unit			(14,161)	(14,161)	(54,268)	(68,429)
Joint ventures distributions					(1,146)	(1,146)
Issuance of common stock upon O.P. Unit conversion	2	15,842		15,844	(15,844)
Issuance of common stock upon O.P. Unit conversion (in shares)	2,122,000
Amortization of stock-based compensation		352		352		352
Balance at Dec. 31, 2009	22	170,606	(25,784)	144,844	452,285	597,129
Balance (in shares) at Dec. 31, 2009	21,870,211
Net income			8,473	8,473	28,022	36,495
Dividends declared per common share and O.P. Unit			(13,209)	(13,209)	(49,962)	(63,171)
Joint ventures distributions					(710)	(710)
Issuance of common stock upon O.P. Unit conversion		1,734		1,734	(1,734)
Issuance of common stock upon O.P. Unit conversion (in shares)	254,700
Amortization of stock-based compensation		161		161		161
Issuance of common stock upon option exercise		67		67		67
Issuance of common stock upon option exercise (in shares)	10,859
Balance at Dec. 31, 2010	22	172,568	(30,520)	142,070	427,901	569,971
Balance (in shares) at Dec. 31, 2010	22,135,770
Net income			9,275	9,275	29,626	38,901
Dividends declared per common share and O.P. Unit			(11,717)	(11,717)	(43,033)	(54,750)
Joint ventures distributions					(1,092)	(1,092)
Issuance of common stock upon O.P. Unit conversion	1	3,275		3,276	(3,276)
Issuance of common stock upon O.P. Unit conversion (in shares)	450,250
Amortization of stock-based compensation		57		57		57
Balance at Dec. 31, 2011	$ 23	$ 175,900	$ (32,962)	$ 142,961	$ 410,126	$ 553,087
Balance (in shares) at Dec. 31, 2011	22,586,020