Acquisitions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 119,965	$ 96,085	$ 45,364
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	(18)	0	0
Land
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	12,811	10,314	9,312
Building and improvements
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	73,502	41,995	26,593
Furniture and fixtures
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	4,612	2,933	1,386
Assembled occupancy acquired
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	895	905	724
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	360	729	0
Off-Market Favorable Lease [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	10,901	28,680	0
Goodwill [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	10,617	6,334	3,197
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 6,285	$ 4,195	$ 4,152