Commitments and Contingencies (Details) $ in Thousands, £ in Millions, SGD in Millions	12 Months Ended					30 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2015 GBP (£)	Dec. 31, 2014 USD ($)	Dec. 31, 2014 GBP (£)	Dec. 31, 2013 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2014 GBP (£)	Dec. 31, 2015 SGD	Jul. 11, 2012 USD ($)	Jul. 11, 2012 GBP (£)
Commitments and Contingencies [Line Items]
Lease term	12 years	12 years
Lease term extension	5 years	5 years
Rent expense	$ 24,600		$ 16,200		$ 23,100
Straight-line rent expense adjustment					10,000
Straight-line rent adjustments related to prior years					7,500
Increase (decrease) in fair value of contingent consideration	(44,276)		(8,093)		(1,762)
Commitments related to construction contracts	157,600
29A International Business Park
Commitments and Contingencies [Line Items]
Additional performance based consideration earned (maximum)	35,200							SGD 50.0
Contingent liability	19,400		12,600			$ 12,600
Sentrum Portfolio
Commitments and Contingencies [Line Items]
Contingent liability									$ 87,600	£ 56.5
Earnout payment	1,100	£ 0.7	10,300	£ 6.2		$ 37,200	£ 23.8
Increase (decrease) in fair value of contingent consideration	(43,000)	£ (30.3)	$ (8,400)		$ (1,800)
Convergence Business Park
Commitments and Contingencies [Line Items]
Sale price of building	24,000
Real estate price, per square acre	$ 225