Derivative Financial Instruments - Impact of Derivatives on Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 794	$ 812
Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative Assets	794	812
Derivative Liabilities	(1,089)	(2,584)
Total net derivatives	(295)	(1,772)
Interest rate swaps | Derivatives Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Derivative Assets	0	182
Derivative Liabilities	(36)	0
Total net derivatives	(36)	182
Interest rate swaps | Cash Flow | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(1,053)	(2,584)
Total net derivatives	(1,053)	(2,584)
Interest rate swaps | Fair Value | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	794	630
Derivative Liabilities	0	0
Total net derivatives	$ 794	$ 630