Leases - NECG Lease Restructuring - Additional Information (Detail) $ in Thousands	1 Months Ended	9 Months Ended
	Jun. 30, 2013 Operator	Sep. 30, 2015 USD ($) Property	Dec. 31, 2014 USD ($)	Aug. 31, 2013 Property
Leases [Line Items]
Number of locations (operators) involved in the proceedings | Operator	24
Number of former operators have withdrawn their appeals | Operator	16
Number of operators remain in the site during their court appeal | Operator	8
Bad debt reserve on accounts receivable		$ 4,489	$ 4,160
Reserved deferred rent receivable		$ 6,101
NECG Holdings Corp [Member]
Leases [Line Items]
Number of leased properties removed | Property		31
Number of properties previously leased | Property				84
Bad debt reserve on accounts receivable		$ 2,035