Derivative Instruments - Gains (Losses) on Derivative Instruments and Classification on Consolidated Statement of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Gains recognized in OCI	$ 52	$ 240	$ 55	$ 726
Losses recognized in OCI	(620)	(7)	(508)	(7)
Gains recognized from accumulated OCI into net loss	52	561	55	1,144
Losses recognized from accumulated OCI into net loss	(73)	0	(89)	0
Not Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Gains recognized in net loss	0	40	0	25
Losses recognized in net loss	$ 0	$ 0	$ 0	$ (15)