Commitments And Contingencies (Details)	3 Months Ended		12 Months Ended						3 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Dec. 31, 2013 Sentrum Portfolio [Member] USD ($)	Dec. 31, 2013 Sentrum Portfolio [Member] GBP (£)	Mar. 31, 2014 Sentrum Portfolio [Member] USD ($)	Mar. 31, 2014 Sentrum Portfolio [Member] GBP (£)	Jul. 11, 2012 Sentrum Portfolio [Member] USD ($)	Jul. 11, 2012 Sentrum Portfolio [Member] GBP (£)	Mar. 31, 2014 29 A International Business Park [Member] USD ($)	Mar. 31, 2014 29 A International Business Park [Member] SGD	Mar. 31, 2014 Convergence Business Park [Member] USD ($)
Commitments and Contingencies [Line Items]
Additional performance based consideration earned (maximum)										50,000,000
Additional performance based consideration earned (maximum), adjusted for exchange rate									39,800,000
Expiration of earnout contingency									November 2020	November 2020
Lease expiration period											April 2017
Sale price of building											24,000,000
Real estate price, per square acre											225,000
Contingent liability					62,000,000	37,200,000	87,600,000	56,500,000
Change in fair value of accrued contingent consideration	(3,403,000)	1,300,000
Earnout payment			25,800,000	16,900,000
Commitments related to construction contracts	$ 281,400,000