Segment Information Related Party (Details) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2015 USD ($) bldg	Sep. 30, 2015 USD ($) a bldg
Land, Buildings and Improvements [Member]
Related Party Transaction [Line Items]
Number of Real Estate Properties Sold in a Related Party Transaction		6	36
Proceeds from Sale of Property in a Related Party Transaction | $		$ 89,784	$ 248,116
Land, Buildings and Improvements [Member] | Richmond Hampton Roads [Member]
Related Party Transaction [Line Items]
Number of Real Estate Properties Sold in a Related Party Transaction		0	22
Proceeds from Sale of Property in a Related Party Transaction | $		$ 0	$ 110,300	[1]
Land, Buildings and Improvements [Member] | Richmond Hampton Roads [Member] | Immediate Family Member of Management or Principal Owner [Member] | Richmond Hampton Roads Sale [Member]
Related Party Transaction [Line Items]
Number of Real Estate Properties Sold in a Related Party Transaction			22
Proceeds from Sale of Property in a Related Party Transaction | $	[1]		$ 110,300
Land and Land Improvements [Member] | Richmond Hampton Roads [Member]
Related Party Transaction [Line Items]
Sold Land, Acres | a			3.1
Land and Land Improvements [Member] | Richmond Hampton Roads [Member] | Immediate Family Member of Management or Principal Owner [Member] | Richmond Hampton Roads Sale [Member]
Related Party Transaction [Line Items]
Sold Land, Acres | a			3.1

[1] Includes proceeds from the sale of 3.1 acres of land.