Derivative Instruments - Gains (Losses) on Derivative Instruments and Classification on Consolidated Statement of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Designated as hedging instrument [Member]
Derivatives, Fair Value [Line Items]
Gains recognized in OCI		$ 427
Gains reclassified from accumulated OCI into net loss		223
Not designated as hedging instrument [Member]
Derivatives, Fair Value [Line Items]
Net gains recognized in net loss		2
Net losses recognized in net loss		$ (57)