Derivative Instruments and Hedging Activities - Fair Value of Company's Derivative Financial Instruments Classification on Consolidated Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value	$ 628
Other Liabilities [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value	628
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value		71
Other Assets [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value		$ 71