Real Estate and Lending Activities - 2015 Activity - Additional Information (Detail) € in Millions, $ in Millions								1 Months Ended	9 Months Ended
	Sep. 09, 2015 EUR (€)	Aug. 31, 2015 USD ($) Investment Bed	Jun. 30, 2015 EUR (€) Property	Jun. 16, 2015 USD ($) Property Bed	Apr. 29, 2015 EUR (€) Hospital	Feb. 27, 2015 USD ($) Leases	Feb. 13, 2015 USD ($) RenewalOptions Facility	Aug. 31, 2015 USD ($) Investment Property Leases	Sep. 30, 2015 USD ($) Hospital Health_Center	Sep. 30, 2015 EUR (€)	Aug. 01, 2015 EUR (€)	Jul. 31, 2015 EUR (€)	Dec. 31, 2014 EUR (€)
Acute Care Hospital [Member]
Business Acquisition [Line Items]
Ownership interest in equity												50.00%
Purchase price of acquisition | €												€ 90.0
Capella Healthcare Inc [Member]
Business Acquisition [Line Items]
Combined purchase price and investment amount		$ 900.0						$ 900.0
Term of lease, years								15 years
Number of lease extension options | Leases								4
Term of lease extension, years								5 years
Number of properties closed | Property								6
Increase in consumer price-index, floor rate								2.00%
Increase in consumer price-index, ceiling rate								4.00%
Ownership interests acquired		49.00%						49.00%
Capella Healthcare Inc [Member] | Acute Care Hospital [Member]
Business Acquisition [Line Items]
Number of portfolio investments | Investment		7						7
Number of investment in form of mortgage loan | Investment		5						5
Joint Venture Partner [Member] | Capella Healthcare Inc [Member]
Business Acquisition [Line Items]
Ownership interests acquired		51.00%						51.00%
Fixed interest rate								8.00%
2015 [Member] | Acute Care Hospital [Member] | Kansas [Member]
Business Acquisition [Line Items]
Term of lease, years							10 years
Term of lease extension, years							5 years
Mortgage financing							$ 40.0
Mortgage financing term							10 years
Number of facilities acquired | Facility							2
Purchase price of acquisition							$ 110.0
Number of lease extension options in current lease contract | RenewalOptions							2
2015 [Member] | General Acute Care Hospital and Healthcare System [Member]
Business Acquisition [Line Items]
Mortgage financing									$ 100.0
Mortgage financing funded									$ 85.0
Number of licensed hospitals | Hospital									3
Number of free-standing emergency department and health center | Health_Center									1
2015 [Member] | Lake Huron Medical Center [Member]
Business Acquisition [Line Items]
Mortgage financing		$ 30.0
Mortgage financing term		5 years
2015 [Member] | Lake Huron Medical Center [Member] | General Acute Care Hospital [Member]
Business Acquisition [Line Items]
Number of beds acquired | Bed		144
2015 [Member] | Ernest Health, Inc [Member]
Business Acquisition [Line Items]
Term of lease, years				20 years
Acquisition costs				$ 31.5
Loans provided for acquisition				$ 12.0
Number of properties acquired | Property				2
2015 [Member] | Ernest Health, Inc [Member] | Minimum [Member]
Business Acquisition [Line Items]
Term of lease extension, years				3 years
2015 [Member] | Ernest Health, Inc [Member] | Maximum [Member]
Business Acquisition [Line Items]
Term of lease extension, years				5 years
2015 [Member] | Ernest Health, Inc [Member] | Rehabilitation Hospital with Covenant Health System [Member]
Business Acquisition [Line Items]
Number of beds acquired | Bed				60
2015 [Member] | Ernest Health, Inc [Member] | Acute Care Hospital [Member]
Business Acquisition [Line Items]
Number of beds acquired | Bed				37
2015 [Member] | Ernest Health, Inc [Member] | Inpatient Rehabilitation Hospital [Member] | Weslaco Texas [Member]
Business Acquisition [Line Items]
Number of lease extension options | Leases						3
Term of lease extension, years						5 years
Acquisition costs						$ 10.7
Payments to fund long-term loans to related parties						$ 5.0
Lease remaining term						17 years
2015 [Member] | Median Kliniken [Member]
Business Acquisition [Line Items]
Term of lease, years					27 years
Number of properties closed | Property			30
Ownership interests acquired													5.10%
Number of hospitals acquired | Hospital					32
Acquisition costs | €					€ 688.0
Lease rate					9.30%
Lease rent increase percentage					70.00%
Loans provided for acquisition | €			€ 240.0										€ 425.0
Value of properties closed | €											€ 627.0
2015 [Member] | Median Kliniken [Member] | Waterland Private Equity Fund [Member]
Business Acquisition [Line Items]
Ownership interests acquired													94.90%
2015 [Member] | Median and Waterland [Member]
Business Acquisition [Line Items]
Loan amount outstanding | €										€ 37.0
Development Activities [Member] | Axa Real Estate [Member]
Business Acquisition [Line Items]
Ownership interest in equity	50.00%
Development Activities [Member] | Axa Real Estate [Member] | Acute Care Hospital [Member]
Business Acquisition [Line Items]
Estimated total development cost | €	€ 21.4