Derivatives and Hedging Activities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016 USD ($) Derivative	Dec. 31, 2015 USD ($) Derivative	Dec. 31, 2014 USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Aggregate notional amount	$ 206,900,000	$ 69,600,000
Collateral posted with market value on liability positions with credit risk-related contingent features	$ 7,200,000
Interest Rate Swap [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of interest rate swaps | Derivative	24	12
Net gain (loss) on change in fair value	$ 500,000	$ 3,000	$ (200,000)
Income (loss) on derivative instrument not designated hedges	2,500,000	200,000	$ 600,000
Interest Rate Lock Commitments [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Aggregate notional amount	19,500,000	14,500,000
Loss on derivative fair value	$ 44,000	$ 20,000