Real Estate and Lending Activities - Adeptus Health - Additional Information (Detail) - Adeptus Health [Member] $ in Millions			3 Months Ended
	Apr. 01, 2018 Property	Jan. 01, 2018 Property	Mar. 31, 2018 USD ($) Property Facility
Business Acquisition [Line Items]
Number of properties closed		5
Number of properties			8
Amortization of straight line rent receivable | $			$ 1.8
Number of facilities expected to sell or re-lease | Facility			16
Subsequent Event [Member]
Business Acquisition [Line Items]
Number of properties closed	3