Interest Rate Hedging - Financial Assets and Liabilities Valued on Recurring Basis (Detail) $ in Thousands	Sep. 30, 2015 USD ($)
Derivatives, Fair Value [Line Items]
Derivative asset	$ 1,609
Derivative liability	(5,084)
Derivative asset and liability, Total	(3,475)
Significant Other Observable Inputs Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative asset	1,609
Derivative liability	(5,084)
Derivative asset and liability, Total	$ (3,475)