Segment Reporting (Schedule of Information for Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Rental and parking expenses	$ (7,099)	$ (4,580)	$ (14,683)	$ (8,321)
Income from operations	22,745	10,179	42,163	20,961
Real estate-related notes receivables interest income	216	1,280	355	2,431
General and administrative expenses	(1,451)	(879)	(2,860)	(1,801)
Change in fair value of contingent consideration	(150)	0	(300)	0
Acquisition related expenses	(509)	(5,286)	(3,654)	(6,511)
Asset management fees	(4,533)	(3,094)	(8,566)	(5,460)
Depreciation and amortization	(16,445)	(10,006)	(32,228)	(18,273)
Other income	2,603	162	3,119	200
Interest expense	(7,004)	(4,238)	(13,310)	(8,427)
Net income	18,344	6,103	31,972	12,734
Operating Segments [Member]
Segment Reporting Information [Line Items]
Rental, parking and tenant reimbursement revenue	52,716	32,744	104,099	58,896
Rental and parking expenses	(7,099)	(4,580)	(14,683)	(8,321)
Income from operations	45,617	28,164	89,416	50,575
Operating Segments [Member] | Data Centers [Member]
Segment Reporting Information [Line Items]
Rental, parking and tenant reimbursement revenue	28,706	19,792	57,819	35,817
Rental and parking expenses	(5,380)	(3,875)	(10,440)	(6,981)
Income from operations	23,326	15,917	47,379	28,836
Operating Segments [Member] | Healthcare [Member]
Segment Reporting Information [Line Items]
Rental, parking and tenant reimbursement revenue	24,010	12,952	46,280	23,079
Rental and parking expenses	(1,719)	(705)	(4,243)	(1,340)
Income from operations	$ 22,291	$ 12,247	$ 42,037	$ 21,739