Fair Value (Recorded Amount of Liabilities Measured at Fair Value on Recurring Basis) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets - interest rate swaps	$ 537	$ 2,244
Derivative liabilities - interest rate swaps	(2,705)	(2,297)
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets - interest rate swaps	537	2,244
Derivative liabilities - interest rate swaps	$ (2,705)	$ (2,297)