Operating Leases - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) Property
Operating Leased Assets [Line Items]
Number of properties owned	0
Triple Net Lease Agreements
Operating Leased Assets [Line Items]
Number of properties owned	86
Weighted average remaining lease term	7 years 1 month 6 days
Total annualized property tax | $	$ 4.6
Triple Net Lease Agreements | Single Tenant Properties
Operating Leased Assets [Line Items]
Number of properties owned	42
Real estate investment properties, percentage leased under operating leases	100.00%
Triple Net Lease Agreements | Multi Tenant Properties
Operating Leased Assets [Line Items]
Number of properties owned	44
Triple Net Lease Agreements | Minimum
Operating Leased Assets [Line Items]
Lease, expiration year	2017
Extended lease period	2 years
Triple Net Lease Agreements | Maximum
Operating Leased Assets [Line Items]
Lease, expiration year	2038
Extended lease period	10 years