Derivative Financial Instruments - Effect of Derivative Instruments on Consolidated Statement of Earnings (Detail) - Derivatives Not Designated as Hedging Instruments [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivatives, Fair Value [Line Items]
Amount of Gain Recognized in Income on Derivative Instruments	$ 327	$ 199	$ 385	$ 199
Interest Rate Swaps [Member] | Other Income [Member]
Derivatives, Fair Value [Line Items]
Amount of Gain Recognized in Income on Derivative Instruments	$ 327	$ 199	$ 385	$ 199