Acquisitions and Dispositions Acquisitions (Details) $ in Thousands	1 Months Ended
	Mar. 31, 2017 store	Jan. 31, 2017 USD ($) store
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		$ 49,663
Building and improvements		16,779
Tenant improvements		4,611
Above-market leases		681
In-place leases		8,943
Total assets		80,677
Below-market leases		(878)
Net assets acquired		$ 79,799
Sears Department Stores
Business Acquisition [Line Items]
Number of stores acquired | store		5
Minimum period of lease before termination (in years)		2 years
Sears Auto Centers
Business Acquisition [Line Items]
Number of stores acquired | store		2
Minimum period of lease before termination (in years)		1 year
Sears Department Stores and Auto Centers
Business Acquisition [Line Items]
Consideration paid		$ 72,765
Transaction costs		$ 265
Term of lease (in years)		10 years
Initial base rent		$ 5,075
Decrease in rent for third through tenth years of leases		0.25%
Required notice period for cancellation of lease (in months)		6 months
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		$ 45,028
Building and improvements		14,814
Tenant improvements		4,234
Above-market leases		681
In-place leases		8,364
Total assets		73,121
Below-market leases		(356)
Net assets acquired		$ 72,765
Jefferson Mall
Business Acquisition [Line Items]
Minimum period of lease before termination (in years)		4 years
Macy's
Business Acquisition [Line Items]
Number of stores acquired | store		4
Consideration paid		$ 7,034
Transaction costs		34
Annual maintenance charge		19
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Land		4,635
Building and improvements		1,965
Tenant improvements		377
Above-market leases		0
In-place leases		579
Total assets		7,556
Below-market leases		(522)
Net assets acquired		$ 7,034
Macy's
Business Acquisition [Line Items]
Number of stores closed | store	3
Above-market leases | Sears Department Stores and Auto Centers
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Weighted average amortization period (in years)		2 years
Above-market leases | Macy's
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Weighted average amortization period (in years)		0 years
In-place leases | Sears Department Stores and Auto Centers
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Weighted average amortization period (in years)		2 years 2 months
In-place leases | Macy's
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Weighted average amortization period (in years)		2 years 1 month 28 days
Below-market leases | Sears Department Stores and Auto Centers
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Weighted average amortization period (in years)		5 years 4 months 20 days
Below-market leases | Macy's
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Weighted average amortization period (in years)		2 years 1 month 28 days