Loans Receivable, Net - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted-average risk rating on loan exposure	2.5	2.2
Impaired loans	$ 0	$ 0
Maturity date	Feb. 28, 2017
Net book value of downgraded asset	$ 20,900,000
Risk Rating 2 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal balance of loan		$ 11,000,000
Risk Rating 4 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal balance of loan	$ 113,300,000