Effect of Derivative Instruments on Consolidated Statement of Operations (Detail) - Designated as Hedging Instrument [Member] - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Loss on Cash Flow Hedge Ineffectiveness	$ 3,000	$ 43,000
Amount of Loss Reclassified from Accumulated OCI into Income (Effective Portion)	(672,000)	(1,186,000)
(Loss) Gain on Cash Flow Hedge Ineffectiveness, Net	(3,000)	(43,000)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) or Gain Recognized in OCI on Derivative (Effective Portion)	$ 2,520,000	$ (3,705,000)