Related Party Transactions (Details) (USD $)	144 Months Ended		12 Months Ended							0 Months Ended		12 Months Ended			76 Months Ended	98 Months Ended	174 Months Ended
	Dec. 31, 2012 nonemployeedirectors	Dec. 31, 2011	Dec. 31, 2012 Brother of Executive Vice President [Member]	Dec. 31, 2011 Brother of Executive Vice President [Member]	Dec. 31, 2010 Brother of Executive Vice President [Member]	Dec. 31, 2012 Director [Member]	Dec. 31, 2011 Director [Member]	Dec. 31, 2010 Director [Member]	Dec. 31, 2012 Son of Director [Member]	Jul. 24, 2007 Former Director [Member]	Jun. 30, 1998 Former Director [Member]	Dec. 31, 2012 Former Director [Member]	Dec. 31, 2007 Former Director [Member]	Dec. 31, 2004 Former Director [Member]	Oct. 20, 2004 Affiliate of Former Director [Member]	Dec. 31, 2012 Affiliate of Former Director [Member]	Dec. 31, 2012 Affiliate of Former Director [Member] sqft Y
Related Party Transaction [Line Items]
Aggregate leasing commissions paid to related parties			$ 1,306,000	$ 671,000	$ 960,000	$ 199,000	$ 24,000	$ 93,000
PercentOwnedOfRelatedParty						95.00%			5.00%
Related Party Acquisition Date										Jul. 24, 2007	Jun. 30, 1998
Square Feet of Development																	2,000,000
Purchase price per rentable square feet of property developed.																	20
Target Annual Return Minimum															10.50%
Target Annual Return Maximum.															11.00%
Annual Development Agreement Payments.												125,000
Development Agreement Payment Made For 1998 Through 2004														750,000
Aggregate Fixed Rentable Per Square Foot Of Developed Property.																10.50
Adjustment To Aggregate Fixed Amount Per Square Foot Of Developed Property																5.50
Term of Development Agreement., Years																	20
Number Of Non employee Directors Electing To Receive Deferred Stock Units	5
Purchase Price of Land Parcel													$ 3,100,000
Deferred Stock Units Outstanding	76,682	79,856