Investments In Real Estate (Summary Of Investment Properties) (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
Real Estate Properties [Line Items]
Land	$ 693,791,000		$ 661,058,000
Acquired Ground Lease	14,618,000		13,658,000
Building And Improvements	8,680,677,000	[1]	7,662,973,000	[1]
Tenant improvements	490,492,000		404,830,000
Accumulated depreciation and amortization	(1,565,996,000)		(1,206,017,000)
Net investments in properties	8,313,582,000		7,536,502,000
Direct and accrued costs associated with work in progress	1,053,200,000		777,300,000
Internet Gateway Datacenters [Member]
Real Estate Properties [Line Items]
Land	117,863,000		117,304,000
Building And Improvements	1,466,490,000	[1]	1,406,586,000	[1]
Tenant improvements	100,481,000		97,007,000
Accumulated depreciation and amortization	(474,646,000)		(399,060,000)
Net investments in properties	1,210,188,000		1,221,837,000
Corporate Datacenters [Member]
Real Estate Properties [Line Items]
Land	534,776,000		516,016,000
Acquired Ground Lease	13,296,000		12,336,000
Building And Improvements	7,031,664,000	[1]	6,108,420,000	[1]
Tenant improvements	382,219,000		300,426,000
Accumulated depreciation and amortization	(1,051,306,000)		(773,449,000)
Net investments in properties	6,910,649,000		6,163,749,000
Technology Manufacturing [Member]
Real Estate Properties [Line Items]
Land	29,147,000		20,602,000
Acquired Ground Lease	1,322,000		1,322,000
Building And Improvements	75,546,000	[1]	66,396,000	[1]
Tenant improvements	5,938,000		5,938,000
Accumulated depreciation and amortization	(24,044,000)		(22,175,000)
Net investments in properties	87,909,000		72,083,000
Technology Office [Member]
Real Estate Properties [Line Items]
Land	9,840,000		4,971,000
Building And Improvements	52,031,000	[1]	34,585,000	[1]
Tenant improvements	1,854,000		1,459,000
Accumulated depreciation and amortization	(10,858,000)		(7,958,000)
Net investments in properties	52,867,000		33,057,000
Other [Member]
Real Estate Properties [Line Items]
Land	2,165,000		2,165,000
Building And Improvements	54,946,000	[1]	46,986,000	[1]
Accumulated depreciation and amortization	(5,142,000)		(3,375,000)
Net investments in properties	$ 51,969,000		$ 45,776,000

[1] Balance includes, as of December 31, 2013 and 2012, $1,053.2 million and $777.3 million of direct and accrued costs associated with construction in progress, respectively.