Fair Values of our Derivative Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 259	[1]	$ 419	[1]
Derivative liabilities	105	[1]	1	[1]
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	259	[1]	419	[1]
Derivative liabilities	$ 105	[1]	$ 1	[1]

[1] Based on observable market transactions of spot and forward rates.