Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 10,718	$ 6,641	$ 4,065
Adjustments to reconcile net income to net cash provided by operating activities
Straight line rents	(2,744)	(3,005)	(2,673)
Amortization of lease intangibles	(1,099)	(864)	399
Depreciation and amortization	19,170	12,481	8,728
Depreciation related to discontinued operations		101	509
Gain on sales of real estate investments		(2,778)	(4,037)
Deferred financing cost and mortgage premium amortization	279	252	462
Stock-based compensation	2,060	2,137	1,121
Changes in assets and liabilities
Other assets	(1,510)	(576)	(533)
Accounts payable and other liabilities	2,447	(894)	1,708
Net cash provided by operating activities	29,321	13,495	9,749
CASH FLOWS FROM INVESTING ACTIVITIES
Restricted cash	(40)	(265)	(218)
Cash paid for property acquisitions	(225,797)	(209,338)	(166,043)
Cash paid for deposits on property acquisitions	(4,350)	(200)
Proceeds from sales of real estate investments		17,469	16,293
Additions to buildings, improvements and leasing costs	(19,729)	(9,531)	(10,212)
Net cash used in investing activities	(249,916)	(201,865)	(160,180)
CASH FLOWS FROM FINANCING ACTIVITIES
Issuance of common stock	320,263	191,475	55,004
Issuance costs on issuance of common stock	(630)	(648)	(305)
Repurchase of common stock	(284)	(160)	(79)
Issuance of preferred stock			44,551
Issuance costs on issuance of preferred stock			(260)
Purchase of derivative instrument	(835)
Borrowings on credit facility	115,000	62,500	162,700
Payments on credit facility	(146,000)	(96,929)	(138,271)
Borrowings on term loan payable	150,000	50,000
Payments on term loan payable			(20,050)
Borrowings on mortgage loans payable			59,880
Payments on mortgage loans payable	(12,267)	(2,852)	(1,847)
Payment of deferred financing costs	(1,705)	(723)	(1,110)
Dividends paid to common stockholders	(15,770)	(9,669)	(5,497)
Dividends paid to preferred stockholders	(3,565)	(3,565)	(1,604)
Net cash provided by financing activities	404,207	189,429	153,112
Net increase in cash and cash equivalents	183,612	1,059	2,681
Cash and cash equivalents at beginning of year	6,989	5,930	3,249
Cash and cash equivalents at end of year	190,601	6,989	5,930
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for interest, net of capitalized interest	6,242	6,413	4,819
Supplemental disclosures of non-cash transactions
Accounts payable related to capital improvements	2,353	1,685	451
Reconciliation of cash paid for property acquisitions
Acquisition of properties	236,747	212,434	185,281
Assumption of mortgage loans payable	(8,497)		(14,832)
Mortgage premiums	(344)		(701)
Assumptions of other assets and liabilities	(2,109)	(3,096)	(3,705)
Net cash paid for property acquisitions	$ 225,797	$ 209,338	$ 166,043