Quarterly Results of Operations (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended
Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Results Of Operations [Abstract]
Total revenues	$ 18,747us-gaap_RealEstateRevenueNet	$ 17,714us-gaap_RealEstateRevenueNet	$ 16,610us-gaap_RealEstateRevenueNet	$ 15,804us-gaap_RealEstateRevenueNet	$ 13,169us-gaap_RealEstateRevenueNet	$ 11,516us-gaap_RealEstateRevenueNet	$ 10,815us-gaap_RealEstateRevenueNet	$ 10,029us-gaap_RealEstateRevenueNet	$ 68,875us-gaap_RealEstateRevenueNet	$ 45,529us-gaap_RealEstateRevenueNet	$ 29,335us-gaap_RealEstateRevenueNet
Total costs and expenses	(14,105)us-gaap_OperatingExpenses	(12,806)us-gaap_OperatingExpenses	(12,230)us-gaap_OperatingExpenses	(12,426)us-gaap_OperatingExpenses	(11,006)us-gaap_OperatingExpenses	(9,131)us-gaap_OperatingExpenses	(8,906)us-gaap_OperatingExpenses	(7,930)us-gaap_OperatingExpenses	(51,567)us-gaap_OperatingExpenses	(36,973)us-gaap_OperatingExpenses	(25,931)us-gaap_OperatingExpenses
Total other income and expenses	(1,868)us-gaap_NonoperatingIncomeExpense	(1,470)us-gaap_NonoperatingIncomeExpense	(1,659)us-gaap_NonoperatingIncomeExpense	(1,593)us-gaap_NonoperatingIncomeExpense	(1,601)us-gaap_NonoperatingIncomeExpense	(1,452)us-gaap_NonoperatingIncomeExpense	(1,537)us-gaap_NonoperatingIncomeExpense	(1,515)us-gaap_NonoperatingIncomeExpense	(6,590)us-gaap_NonoperatingIncomeExpense	(6,105)us-gaap_NonoperatingIncomeExpense	(5,435)us-gaap_NonoperatingIncomeExpense
Income from continuing operations	2,774	3,438	2,721	1,785	562	933	372	584	10,718	2,451	(2,031)
Income from discontinued operations					360	392	450	210		1,412	2,059
Gain on sales of real estate investments					2,778					2,778	4,037
Net income (loss) available to common stockholders, net of preferred stock dividends	$ 1,880	$ 2,535	$ 1,823	$ 888	$ 2,790	$ 432	$ (69)	$ (97)	$ 7,126	$ 3,056	$ 2,437
Income (loss) from continuing operations available to common stockholders, net of preferred stock dividends	$ 0.05	$ 0.08	$ 0.06	$ 0.04	$ (0.01)		$ (0.02)	$ (0.01)	$ 0.23	$ (0.05)	$ (0.28)
Income from discontinued operations					$ 0.12	$ 0.02	$ 0.02			$ 0.20	$ 0.47
Net income (loss) available to common stockholders, net of preferred stock dividends	$ 0.05us-gaap_EarningsPerShareBasicAndDiluted	$ 0.08us-gaap_EarningsPerShareBasicAndDiluted	$ 0.06us-gaap_EarningsPerShareBasicAndDiluted	$ 0.04us-gaap_EarningsPerShareBasicAndDiluted	$ 0.11us-gaap_EarningsPerShareBasicAndDiluted	$ 0.02us-gaap_EarningsPerShareBasicAndDiluted		$ (0.01)us-gaap_EarningsPerShareBasicAndDiluted	$ 0.23us-gaap_EarningsPerShareBasicAndDiluted	$ 0.15us-gaap_EarningsPerShareBasicAndDiluted	$ 0.19us-gaap_EarningsPerShareBasicAndDiluted
Basic and Diluted Weighted Average Common Shares Outstanding	35,381,477	32,937,432	28,419,154	24,850,760	24,833,304	24,208,008	19,076,760	15,792,553	30,433,017	21,011,276	13,135,440

After tax income (loss) from operations of a business component (exclusive of any gain (loss) on disposal, or provision therefore) during the reporting period, until its disposal.

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This element represents the amount of gain (loss) on sale of properties during the reporting period net of the applicable income taxes realized.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

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The aggregate revenue from real estate operations during the reporting period.

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