Allowance for Loan Losses - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) Contract	Mar. 31, 2016 USD ($) Contract	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Receivables [Abstract]
Allowance for loans receivable | $	$ 15,716	$ 17,952	$ 15,541	$ 18,008
Ratio of allowance for loan losses to gross loans held-for-investment	0.98%		0.97%
Loan not considered as impaired	Less than 90 days
Number of TDR's included in Impaired Loans	14
TDRs included in impaired loans | $	$ 2,300
Number of impaired loans in accruing status	4
TDR with commitments to lend additional funds	0
Number new TDR agreements	0	0
Number of TDR agreements that subsequently defaulted	0	0