Real Property Acquisitions and Development (Details 2) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Real estate held-for-sale	$ 619,141		$ 734,147
Triple Net
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Land and land improvements	413,588	$ 31,948
Buildings and improvements	2,239,422	206,910
Acquired lease intangibles	12,383	0
Real estate held-for-sale	396,265	0
Receivables and other assets	1,322	0
Total assets acquired	3,062,980	238,858
Accrued expenses and other liabilities	(13,199)	(21,236)
Total liabilities assumed	(13,199)	(21,236)
Noncontrolling interests	(512,741)	(7,275)
Non-cash acquisition related activity	0	(54,901)
Cash disbursed for acquisitions	2,537,040	155,446
Construction in progress additions	49,619	106,186
Less: Capitalized Interest	(1,932)	(3,886)
Less: Foreign currency translation	180	(656)
Cash disbursed for construction in progress	47,867	101,644
Capital improvements to existing properties	6,766	17,873
Total cash invested in real property	2,591,673	274,963
Cash acquired from acquisition	386,894
Non cash acquisition financed as equity investments		54,901
Senior housing - operating
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Land and land improvements	47,865	31,006
Buildings and improvements	535,436	384,522
Acquired lease intangibles	68,084	48,197
Receivables and other assets	1,255	3,164
Total assets acquired	652,640	466,889
Secured debt	(89,973)	0
Accrued expenses and other liabilities	(14,686)	(43,364)
Total liabilities assumed	(104,659)	(43,364)
Noncontrolling interests	(9,818)	(4,701)
Non-cash acquisition related activity	0	(59,065)
Cash disbursed for acquisitions	538,163	359,759
Construction in progress additions	28,222	65,282
Less: Capitalized Interest	(2,608)	(5,996)
Less: Foreign currency translation	2,151	(6,218)
Cash disbursed for construction in progress	27,765	53,068
Capital improvements to existing properties	127,274	110,372
Total cash invested in real property	693,202	523,199
Cash acquired from acquisition	2,442	6,273
Non cash acquisition financed as real estate loan receivable		6,349
Non cash acquisition financed as equity investments		51,097
Outpatient Medical
Estimated Fair Value of Allocated Purchase Price of Asset and Liabilities
Land and land improvements	18,496	25,060
Buildings and improvements	79,205	62,336
Acquired lease intangibles	11,271	8,397
Real estate held-for-sale	22,032	0
Receivables and other assets	6	3
Total assets acquired	131,010	95,796
Secured debt	(14,769)	(25,709)
Accrued expenses and other liabilities	(910)	(2,210)
Total liabilities assumed	(15,679)	(27,919)
Noncontrolling interests	0	(9,080)
Cash disbursed for acquisitions	115,331	58,797
Construction in progress additions	16,733	33,495
Less: Capitalized Interest	(1,817)	(1,847)
Less: Accruals	(2,402)	11,708
Cash disbursed for construction in progress	12,514	43,356
Capital improvements to existing properties	39,595	30,897
Total cash invested in real property	167,440	133,050
Cash acquired from acquisition	$ 2,244	$ 0