Subsequent Events (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended	6 Months Ended	1 Months Ended	3 Months Ended	6 Months Ended	0 Months Ended
	Jun. 30, 2013	Jun. 30, 2013	Jul. 19, 2013 Orlando, FL Office Properties Acquisition (7/2013) [Member] property sqft	Jun. 30, 2013 Highwoods Properties, Inc. [Member]	Jun. 30, 2013 Highwoods Properties, Inc. [Member]	Jul. 10, 2013 Highwoods Properties, Inc. [Member] ATM 2012 Equity Sales Offering [Member]
Subsequent Event [Line Items]
Number of Common Stock sold at the market during period (in shares)				1,756,590	3,056,381	515,536
Average price of Common Stock sold at the market during period (in dollars per share)				$ 38.32	$ 37.31	$ 35.21
Net proceeds of Common Stock sold at the market during period				$ 66.3	$ 112.3	$ 17.9
Percentage of equity interest acquired in unconsolidated affiliate (in hundredths)			60.00%
Percentage of equity interest in joint ventures, maximum (in hundredths)	50.00%	50.00%	40.00%
Number of office properties acquired			5
Rentable square feet of acquisition (in sq. ft)			1,300,000
Purchase price of acquisition			113.3
Fair value of assets recorded from the acquisition			188.9
Fair value of debt assumed from the acquisition			127.9
Effective interest rate of secured debt assumed from the acquisition (in hundredths)			3.11%
Maturity date of debt assumed from the acquisition			Jul. 01, 2014
Acquisition-related costs	0.4	0.9	0.1
Gain on acquisition of controlling interests in joint venture			$ 7