Real Estate - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016
Real Estate Properties [Line Items]
Weighted average lease term remaining	4 years
Minimum lease payments on leases periods	Greater than one year
Minimum [Member]
Real Estate Properties [Line Items]
Operating leases lease term	1 year
Maximum [Member]
Real Estate Properties [Line Items]
Operating leases lease term	73 years