Liabilities Carried at Fair Value Measured on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	$ 2,389	$ 3,005
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities at fair value	2,389	3,005
Forward Starting Interest Rate Swap Agreement
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Carrying Value	2,389	3,005
Liabilities at fair value	2,389	3,005
Forward Starting Interest Rate Swap Agreement | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities at fair value	$ 2,389	$ 3,005