After Tax (Gain)/Loss Reclassified from Accumulated Other Comprehensive Income into Income (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
After Tax Gain/(Loss) Recognized in OCI, Total	$ 6,876	$ 8,005	$ 2,081
Interest rate swap
Derivative Instruments, Gain (Loss) [Line Items]
After Tax Gain/(Loss) Recognized in OCI, Total	7,032	8,330	2,248
Foreign Exchange Contracts
Derivative Instruments, Gain (Loss) [Line Items]
After Tax Gain/(Loss) Recognized in OCI, Total	$ (156)	$ (325)	$ (167)