Real Estate and Loans Receivable - Loans - Additional Information (Detail) - USD ($) $ in Thousands					1 Months Ended	12 Months Ended
	Oct. 03, 2016	Oct. 01, 2016	Apr. 30, 2016	Mar. 01, 2012	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Mortgage financing						$ 612,836	$ 380,000	$ 12,500
Existing mortgage loans						$ 1,060,336	$ 757,500	$ 397,500	$ 388,650
Amount of convertible note converted into equity interest				$ 1,700
Convertible note				$ 5,000
Percentage of equity shares from convertible debt		15.10%		9.90%		25.00%
Remaining convertible debt after conversion of part of debt						$ 3,300
Capella [Member]
Business Acquisition [Line Items]
Outstanding loans paid						489,000
Steward [Member] | 2016 [Member]
Business Acquisition [Line Items]
Increase in mortgage loans	$ 600,000
Capella [Member]
Business Acquisition [Line Items]
Proceeds from prepayment of mortgage loans			$ 210,000
Mortgage financing			$ 93,300
General Acute Care Hospital and Healthcare System [Member] | 2016 [Member]
Business Acquisition [Line Items]
Mortgage financing					$ 100,000
Ernest Transaction and Other Acquisitions [Member]
Business Acquisition [Line Items]
Existing mortgage loans						$ 115,000