Derivative Financial Instruments (Schedule of Carrying Amount of Hedged Assets/(Liabilities)) (Detail) - Fair Value Hedging - Designated as Hedging Instrument - Interest Rate Swap $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)
Derivative [Line Items]
Carrying Amount of the Hedged Assets/(Liabilities)	$ 116,991	$ 116,991
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)		(5,589)
Cumulative Amount of Fair Value Hedging Adjustment Remaining for any Hedged Assets (Liabilities) for which Hedge Accounting has been Discontinued	0	0
Amount of Gain or (Loss) Recognized in Income on Derivative	$ 15	$ 0