Debt (Narrative) (Details) (USD $)			0 Months Ended								0 Months Ended					6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended		6 Months Ended			0 Months Ended
	Jun. 30, 2014 CollateralizedProperties	Dec. 31, 2013	Jun. 19, 2013 Mercado at Scottsdale Ranch [Member]	Feb. 04, 2013 Credit Facility Base Rate [Member]	Feb. 04, 2013 Credit Facility London Interbank Offered Rate (LIBOR)	Feb. 04, 2013 Term loan	May 31, 2013 Refinanced Debt	Dec. 23, 2013 Woodlake Note [Member]	Sep. 26, 2013 Uptown Note [Member]	Sep. 24, 2013 Terravita Note [Member]	Sep. 24, 2013 Terravita Note [Member] London Interbank Offered Rate (LIBOR)	May 31, 2013 Pinnacle Note [Member]	Jun. 30, 2014 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Credit Facility	Feb. 04, 2013 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Credit Facility	Jun. 30, 2014 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Floating rate notes	Jun. 30, 2014 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Floating rate notes London Interbank Offered Rate (LIBOR)	Dec. 31, 2013 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Floating rate notes London Interbank Offered Rate (LIBOR)	Jun. 30, 2014 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Floating rate notes London Interbank Offered Rate (LIBOR) Minimum	Dec. 31, 2013 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Floating rate notes London Interbank Offered Rate (LIBOR) Minimum	Jun. 30, 2014 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Floating rate notes London Interbank Offered Rate (LIBOR) Maximum	Dec. 31, 2013 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Floating rate notes London Interbank Offered Rate (LIBOR) Maximum	Jun. 30, 2014 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Term loan	Jun. 30, 2014 Unsecured line of credit, LIBOR plus 1.75% to 2.50%, due February 3, 2017 Term loan London Interbank Offered Rate (LIBOR)	Dec. 16, 2013 Anthem Note [Member]	Sep. 26, 2013 Industrial Note [Member]	Nov. 26, 2013 Floating Rate Loan [Member]	Nov. 26, 2013 Fixed Rate Indebtedness [Member]
Debt Instrument [Line Items]
Face amount of debt			$ 11,100,000			$ 50,000,000	$ 14,100,000	$ 6,500,000	$ 16,500,000	$ 10,500,000		$ 20,200,000										$ 50,000,000		$ 15,100,000	$ 37,000,000
Stated interest rate			5.87%				5.695%	3.80%	4.97%			4.2805%										0.84%		4.99%	3.76%
Extinguishment of debt																										26,900,000	10,100,000
Interest supplement assumed with acquisition of real estate			932,000
Imputed interest rate			3.052%
Secured debt	125,800,000
Number of collateralized properties (in collateralized properties)	17
Carrying value of collateralized properties	157,600,000
Credit facility, maximum borrowing capacity														125,000,000
Credit facility, expanded maximum borrowing capacity														225,000,000
Description of variable rate basis				Base Rate	LIBOR						LIBOR					LIBOR	LIBOR						LIBOR
Basis spread on variable rate				0.50%	1.00%						2.00%							1.75%	1.75%	2.50%	2.50%
Line of credit outstanding															137,800,000
Credit facility, remaining borrowing capacity													37,200,000
Notes payable	$ 264,123,000	$ 264,277,000														$ 87,800,000	$ 84,800,000