Segment Reporting (Tables)
3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Segment Reporting [Abstract]    
Schedule of Information for Reportable Segments
Summary information for the reportable segments during the three months ended March 31, 2019 and 2018, is as follows (amounts in thousands):
 
Data Centers
 
Healthcare
 
Three Months Ended
March 31, 2019
Revenue:
 
 
 
 
 
Rental revenue
$
26,677

 
$
19,790

 
$
46,467

Expenses:
 
 
 
 
 
Rental expenses
(6,965
)
 
(2,163
)
 
(9,128
)
Segment net operating income
$
19,712

 
$
17,627

 
37,339

 
 
 
 
 
 
Expenses:
 
 
 
 
 
General and administrative expenses
 
 
 
 
(1,403
)
Asset management fees
 
 
 
 
(3,494
)
Depreciation and amortization
 
 
 
 
(18,246
)
Income from operations
 
 
 
 
14,196

Interest and other expense, net
 
 
 
 
(9,835
)
Net income attributable to common stockholders
 
 
 
 
$
4,361

 
Data Centers
 
Healthcare
 
Three Months Ended
March 31, 2018
Revenue:
 
 
 
 
 
Rental revenue
$
23,721

 
$
17,573

 
$
41,294

Expenses:
 
 
 
 
 
Rental expenses
(5,937
)
 
(2,353
)
 
(8,290
)
Segment net operating income
$
17,784

 
$
15,220

 
33,004


 
 
 
 
 
Expenses:
 
 
 
 
 
General and administrative expenses
 
 
 
 
(943
)
Asset management fees
 
 
 
 
(3,099
)
Depreciation and amortization
 
 
 
 
(13,717
)
Income from operations
 
 
 
 
15,245

Interest and other expense, net
 
 
 
 
(7,741
)
Net income attributable to common stockholders
 
 
 
 
$
7,504

Summary information for the reportable segments during the years ended December 31, 2018, 2017 and 2016, is as follows (amounts in thousands):
 
Data Centers
 
Healthcare
 
For the Year Ended
December 31, 2018
Revenue:
 
 
 
 
 
Rental, parking and tenant reimbursement revenue
$
103,226

 
$
74,106

 
$
177,332

Expenses:
 
 
 
 
 
Rental and parking expenses
(27,289
)
 
(10,038
)
 
(37,327
)
Segment net operating income
$
75,937

 
$
64,068

 
140,005

 
 
 
 
 
 
Expenses:
 
 
 
 
 
General and administrative expenses
 
 
 
 
(5,396
)
Asset management fees
 
 
 
 
(13,114
)
Depreciation and amortization
 
 
 
 
(58,258
)
Income from operations
 
 
 
 
63,237

Interest and other expense, net
 
 
 
 
(34,364
)
Net income attributable to common stockholders
 
 
 
 
$
28,873

 
Data Centers
 
Healthcare
 
For the Year Ended
December 31, 2017
Revenue:
 
 
 
 
 
Rental, parking and tenant reimbursement revenue
$
62,377

 
$
62,718

 
$
125,095

Expenses:
 
 
 
 
 
Rental and parking expenses
(17,571
)
 
(8,525
)
 
(26,096
)
Segment net operating income
$
44,806

 
$
54,193

 
98,999


 
 
 
 
 
Expenses:
 
 
 
 
 
General and administrative expenses
 
 
 
 
(4,069
)
Asset management fees
 
 
 
 
(9,963
)
Depreciation and amortization
 
 
 
 
(41,133
)
Income from operations
 
 
 
 
43,834

Interest and other expense, net
 
 
 
 
(22,555
)
Net income attributable to common stockholders
 
 
 
 
$
21,279

 
Data Centers
 
Healthcare
 
For the Year Ended
December 31, 2016
Revenue:
 
 
 
 
 
Rental, parking and tenant reimbursement revenue
$
12,929

 
$
43,502

 
$
56,431

Expenses:
 
 
 
 
 
Rental and parking expenses
(2,509
)
 
(5,655
)
 
(8,164
)
Segment net operating income
$
10,420

 
$
37,847

 
48,267

 
 
 
 
 
 
Expenses:
 
 
 
 
 
General and administrative expenses
 
 
 
 
(3,105
)
Acquisition related expenses
 
 
 
 
(5,339
)
Asset management fees
 
 
 
 
(4,925
)
Depreciation and amortization
 
 
 
 
(19,211
)
Income from operations
 
 
 
 
15,687

Interest and other expense, net
 
 
 
 
(4,390
)
Net income attributable to common stockholders
 
 
 
 
$
11,297

Schedule of Assets by Reportable Segments
Assets by each reportable segment as of March 31, 2019 and December 31, 2018 are as follows (amounts in thousands):
 
March 31, 2019
 
December 31, 2018
Assets by segment:
 
 
 
Data centers
$
1,008,793

 
$
1,001,357

Healthcare
893,057

 
900,114

All other
59,179

 
62,358

Total assets
$
1,961,029

 
$
1,963,829

Assets by each reportable segment as of December 31, 2018 and December 31, 2017 are as follows (amounts in thousands):
 
December 31, 2018
 
December 31, 2017
Assets by segment:
 
 
 
Data centers
$
1,001,357

 
$
909,477

Healthcare
900,114

 
813,742

All other
62,358

 
54,725

Total assets
$
1,963,829

 
$
1,777,944

Schedule of Capital Additions and Acquisitions by Reportable Segments
Capital additions and acquisitions by reportable segments for the three months ended March 31, 2019 and 2018 are as follows (amounts in thousands):
 
Three Months Ended
March 31,
 
2019
 
2018
Capital additions and acquisitions by segment:
 
 
 
Data centers
$
995

 
$
52,213

Healthcare
78

 
5,629

Total capital additions and acquisitions
$
1,073

 
$
57,842

Capital additions and acquisitions by reportable segments for the years ended December 31, 2018, 2017 and 2016 are as follows (amounts in thousands):
 
For the Year Ended
December 31,
 
2018
 
2017
 
2016
Capital additions and acquisitions by segment:
 
 
 
 
 
Data centers
$
114,944

 
$
472,438

 
$
314,030

Healthcare
117,971

 
164,445

 
229,670

Total capital additions and acquisitions
$
232,915

 
$
636,883

 
$
543,700