Derivative Instruments and Hedging Activities - Fair Value of Company's Derivative Financial Instruments Classification on Unaudited Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivatives Fair Value [Line Items]
Asset Derivatives Fair Value	$ 301	$ 3,109
Other Assets [Member]
Derivatives Fair Value [Line Items]
Asset Derivatives Fair Value	300	3,100
Interest Rate Swaps [Member] | Other Assets [Member]
Derivatives Fair Value [Line Items]
Asset Derivatives Fair Value	$ 301	$ 3,109