Consolidated Statement of Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Shares	Additional Paid-in Capital	Accumulated dividends in excess of net income	Noncontrolling Interests - Unitholders in the Operating Partnership
Beginning Balance at Dec. 31, 2012	$ 685,729	$ 397	$ 663,589	$ (25,625)	$ 47,368
Beginning Balance (in shares) at Dec. 31, 2012	39,664,212	39,664,212
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,429			6,580	2,849
Common shares issued (in shares)		718,714
Common shares issued	24,353	7	24,346
Conversion of operating partnership units (in shares)	61,511	61,511
Conversion of operating partnership units	0	1	1,179		(1,180)
Issuance of restricted stock (in shares)		5,004
Issuance of restricted stock	0	0
Forfeiture of restricted stock (in shares)		(3,863)
Forfeiture of restricted stock	0	0
Dividends declared and paid	(24,380)			(16,823)	(7,557)
Stock-based compensation	1,393		1,393
Ending Balance at Jun. 30, 2013	$ 696,524	$ 405	$ 690,507	$ (35,868)	$ 41,480
Ending Balance (in shares) at Jun. 30, 2013	40,445,578	40,445,578