Fair Value Measurements (Narrative) (Details)	3 Months Ended
	Mar. 31, 2018 USD ($) property	Dec. 31, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of fixed rate mortgage loans payable	$ 125,900,000	$ 127,700,000
Carrying value of fixed rate mortgage payable	$ 127,200,000	128,000,000
Number of properties | property	59
Real estate held for sale	$ 4,120,000
Nonrecurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value		$ 0
Real estate held for sale	4,120,000
Nonrecurring Basis [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate held for sale	$ 4,120,000
Nonrecurring Basis [Member] | Level 3 [Member] | Assets [Member] | Retail Properties [Member] | Income Capitalization Approach [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of properties | property	2
Real estate held for sale	$ 4,100,000
Nonrecurring Basis [Member] | Level 3 [Member] | Assets [Member] | Retail Properties [Member] | Income Capitalization Approach [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization rates	8.50%
Nonrecurring Basis [Member] | Level 3 [Member] | Assets [Member] | Retail Properties [Member] | Income Capitalization Approach [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization rates	9.50%