Real Estate (Details) (USD $)	3 Months Ended								12 Months Ended			0 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	Dec. 24, 2014	Dec. 19, 2014	Nov. 05, 2014	Sep. 19, 2014	Jul. 01, 2014	Dec. 05, 2013 sqft	Oct. 17, 2013 acre sqft	Oct. 07, 2013 sqft	Jun. 28, 2013 acre sqft	Jun. 19, 2013 sqft	Mar. 28, 2013 sqft	Dec. 28, 2012 sqft	Sep. 21, 2012 sqft	Aug. 08, 2012 sqft	May 29, 2012 sqft	Dec. 31, 2014	Jul. 22, 2011	May 31, 2013
Real Estate Properties [Line Items]
Payments to acquire property									$ 129,439,000	$ 119,102,000	$ 98,350,000
Face amount of debt																													14,100,000
INCOME STATEMENT DATA
Operating revenue									82,818,000	81,798,000	79,445,000
Net income									10,910,000	10,422,000	9,072,000
Acquisition-related costs									1,341,000	1,010,000	698,000
Gain on property dispositions									(111,000)	(49,000)	(97,000)
Operating results for properties classified as discontinued operations
Operating income from discontinued operations									510,000	298,000	218,000
Gain on sale of property from discontinued operations									1,887,000	0	0
Income from discontinued operations	2,023,000	109,000	145,000	120,000	41,000	43,000	101,000	113,000	2,397,000	298,000	218,000
Village Square at Dana Park Hard Corner [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)												12,047
Property acquisitions, purchase price												4,700,000
Payments to acquire property												2,100,000
Property percentage occupied												88.00%
Face amount of debt												2,600,000
Revenue since date of acqusition included in results of operations									10,000
Income (loss) since date of acqusition included in results of operations									6,000
The Shops at Williams Trace [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)												132,991
Payments to acquire property												20,200,000
Property percentage occupied												87.00%
Revenue since date of acqusition included in results of operations									49,000
Income (loss) since date of acqusition included in results of operations									41,000
Williams Trace Plaza [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)												129,222
Payments to acquire property												20,400,000
Property percentage occupied												95.00%
Revenue since date of acqusition included in results of operations									40,000
Income (loss) since date of acqusition included in results of operations									32,000
Fulton Ranch Towne Center Adjacent Parcel [Member]
Real Estate Properties [Line Items]
Payments to acquire property													900,000
Area of land (in acres)													1.39
Fulton Ranch Towne Center [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)														113,281
Payments to acquire property														29,300,000
Property percentage occupied														86.00%
Revenue since date of acqusition included in results of operations									399,000
Income (loss) since date of acqusition included in results of operations									228,000
The Promenade at Fulton Ranch [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)														98,792
Payments to acquire property														18,600,000
Property percentage occupied														76.00%
Revenue since date of acqusition included in results of operations									283,000
Income (loss) since date of acqusition included in results of operations									146,000
The Strand at Huebner Oaks [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)															73,920
Payments to acquire property															18,000,000
Property percentage occupied															90.00%
Revenue since date of acqusition included in results of operations									553,000
Income (loss) since date of acqusition included in results of operations									339,000
Heritage Trace Plaza [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																70,431
Payments to acquire property																20,100,000
Property percentage occupied																98.00%
Revenue since date of acqusition included in results of operations									938,000
Income (loss) since date of acqusition included in results of operations									473,000
Market Street at DC Ranch [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																	241,280
Payments to acquire property																	37,400,000
Property percentage occupied																	80.00%
Corporate Park Woodland Parcel [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																		16,220
Payments to acquire property																		2,800,000
Property percentage occupied																		63.00%
Area of land (in acres)																		2.50
Fountain Hills Plaza [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																			111,289
Payments to acquire property																			20,600,000
Property percentage occupied																			87.00%
Anthem Marketplace [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																				113,293
Payments to acquire property																				23,300,000
Property percentage occupied																				100.00%
Area of land (in acres)																				0.83
Mercado at Scottsdale Ranch [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																					118,730
Property acquisitions, purchase price																					21,300,000
Payments to acquire property																					9,300,000
Property percentage occupied																					100.00%
Face amount of debt																					11,100,000
Mercado at Scottsdale Ranch [Member] | Interest Rate Supplement [Member]
Real Estate Properties [Line Items]
Face amount of debt																					900,000
Headquarters Village Shopping Center [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																						89,134
Payments to acquire property																						25,700,000
Property percentage occupied																						100.00%
Shops at Pecos Ranch [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																							78,767
Payments to acquire property																							19,000,000
Property percentage occupied																							100.00%
Village Square at Dana Park [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																								310,979
Payments to acquire property																								46,500,000
Property percentage occupied																								71.00%
Village Square at Dana Park Adjacent Parcel [Member]
Real Estate Properties [Line Items]
Payments to acquire property																								4,000,000
Area of land (in acres)																								4.7
Fountain Square [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																								118,209
Payments to acquire property																								15,400,000
Property percentage occupied																								76.00%
Paradise Plaza [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																									125,898
Property acquisitions, purchase price																									16,300,000
Payments to acquire property																									7,100,000
Property percentage occupied																									100.00%
Paradise Plaza [Member] | Floating Rate Notes [Member]
Real Estate Properties [Line Items]
Face amount of debt																									9,200,000
Shops at Pinnacle Peak [Member]
Real Estate Properties [Line Items]
Gross leasable area (in square feet)																										41,530
Payments to acquire property																										6,400,000
Property percentage occupied																										76.00%
Zeta, Royal Crest and Featherwood [Member]
INCOME STATEMENT DATA
Proceeds from sale of real estate																												10,300,000
Short-term seller financing provided	2,500,000								2,500,000																		2,500,000
Gain on property dispositions									1,900,000																		4,400,000
Deferred gain on sale of property	2,500,000								2,500,000																		2,500,000
Operating results for properties classified as discontinued operations
Property revenues									1,626,000	1,653,000	1,560,000
Property expenses									734,000	832,000	797,000
Depreciation and amortization									314,000	329,000	340,000
Interest expense									58,000	175,000	179,000
Provision for income taxes									10,000	12,000	11,000
Loss on sale or disposal of assets									0	7,000	15,000
Operating income from discontinued operations									510,000	298,000	218,000
Gain on sale of property from discontinued operations									1,887,000	0	0
Income from discontinued operations									$ 2,397,000	$ 298,000	$ 218,000
Wholly Owned Properties [Member]
Real Estate Properties [Line Items]
Number of commercial properties (in commerical property)	63				60				63	60	51																63
Gross leasable area (in square feet)	5,500,000								5,500,000																		5,500,000