Property Transactions (Details) (USD $) In Thousands, unless otherwise specified	11 Months Ended	12 Months Ended
	Nov. 30, 2011 sqft	Dec. 31, 2011 King Mill Distribution Park Suburban Atlanta, GA [Member] sqft	Dec. 31, 2011 Lakeside Ranch Business Park Dallas, TX [Member] sqft	Dec. 31, 2011 One Georgia Center Atlanta, GA [Member] sqft	Dec. 31, 2011 Jefferson Mill Business Park - Building A Suburban Atlanta, GA [Member] sqft	Dec. 31, 2011 8995 Westside Parkway, Atlanta GA [Member] sqft	Dec. 31, 2011 San Jose MarketCenter, San Jose CA [Member] sqft
Summary of sales in discontinued operations
Area of disposed real estate assets	775,000	796,000	749,000	376,000	459,000	51,000	213,000
Sales price of property sold, discontinued operations		$ 28,300	$ 28,400	$ 48,600	$ 22,000	$ 3,200	$ 85,000