Notional or Contractual Amounts and Fair Value of Derivative Instruments (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Feb. 28, 2014
Derivative [Line Items]
Notional or Contractual Amount	$ 4,835,000	$ 5,151,000
Derivative Assets	0	0
Derivative liabilities	167,000	251,000
Interest Rate Swaps Agreement
Derivative [Line Items]
Notional or Contractual Amount			$ 1,200,000	$ 4,370,000
Interest Rate Swaps Agreement | Designated as Hedging Instrument
Derivative [Line Items]
Notional or Contractual Amount	4,835,000	5,151,000
Derivative Assets	0	0
Derivative liabilities	$ 167,000	$ 251,000