Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013 Property	Dec. 31, 2013 Rental Revenues Hampton Roads properties	Dec. 31, 2012 Rental Revenues Hampton Roads properties	Dec. 31, 2011 Rental Revenues Hampton Roads properties	Dec. 31, 2013 Rental Revenues Town Center Properties	Dec. 31, 2012 Rental Revenues Town Center Properties	Dec. 31, 2011 Rental Revenues Town Center Properties	Dec. 31, 2013 Rental Revenues Richmond Tower	Dec. 31, 2012 Rental Revenues Richmond Tower	Dec. 31, 2011 Rental Revenues Richmond Tower	Dec. 31, 2013 Rental Revenues Williams Mullen	Dec. 31, 2012 Rental Revenues Williams Mullen	Dec. 31, 2011 Rental Revenues Williams Mullen	Dec. 31, 2013 General contracting and real estate services revenues Three Customers	Dec. 31, 2012 General contracting and real estate services revenues Two Customers	Dec. 31, 2011 General contracting and real estate services revenues Two Customers	Dec. 31, 2013 Construction receivables Three Customers	Dec. 31, 2012 Construction receivables Two Customers	Dec. 31, 2013 Minimum	Dec. 31, 2013 Minimum Rental Revenues Williams Mullen	Dec. 31, 2013 Maximum
Loss Contingencies [Line Items]
Line of credit, performance and payment bonds	$ 34.0			$ 35.8
Outstanding letters of credit				3.0
Number of ground leases				4
Number of properties				3
Initial terms of leases																						20 years		50 years
Option to extend lease terms, maximum				40 years
Ground rent expense	$ 1.5	$ 1.5	$ 1.3
Concentrations of Credit Risk					70.00%	75.00%	76.00%	48.00%	51.00%	52.00%	15.00%	16.00%	16.00%	16.00%	17.00%	17.00%	50.00%	37.00%	83.00%	69.00%	18.00%
Area of Richmond Tower occupied																							80.00%