Annual report pursuant to Section 13 and 15(d)

Derivative Instruments and Hedging Activities - Additional Information (Detail)

v2.4.0.6
Derivative Instruments and Hedging Activities - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
 1 Months Ended 12 Months Ended 12 Months Ended
Aug. 31, 2009
Agreement
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2009
Dec. 31, 2012
Minimum [Member]
Dec. 31, 2012
Maximum [Member]
Dec. 31, 2012
Interest Rate Swaps [Member]
Dec. 31, 2011
Interest Rate Swaps [Member]
Dec. 31, 2009
Interest Rate Swaps [Member]
Dec. 31, 2012
Foreign exchange currency contracts [Member]
Dec. 31, 2011
Foreign exchange currency contracts [Member]
Dec. 31, 2012
Freestanding Derivatives [Member]
Dec. 31, 2011
Freestanding Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]                          
Maximum duration of hedging of interest rate swap derivative exposure   7 months                      
Number of interest rate swap agreements 4                        
Interest rate swap agreements, aggregate notional amounts       $ 140.0                  
Weighted average fixed interest rate on notional amounts                 2.78%        
Interest rate applicable on interest rate swap agreements for stipulated period                 1 month LIBOR rate        
Expiration date of interest rate swap agreements             Jul. 31, 2013 Jul. 31, 2013 Jul. 31, 2013        
Effective date of interest rate swap agreements                 Dec. 31, 2009        
Interest on credit facility         LIBOR + 1.50 LIBOR + 2.50              
Average effective fixed rate on notional balances of debt and interest rate swap, minimum   4.28%                      
Average effective fixed rate on notional balances of debt and interest rate swap, maximum   5.28%                      
Liabilities related to Interest rate swaps at fair value             2.0 5.1          
Outstanding notional amount of foreign currency forward contract   610.1 318.8             256.9 64.4    
Expected maturity period of foreign currency forward contracts                   12 months      
Fair value of outstanding foreign currency forward contracts                   0.5 4.4    
Derivative liability fair value                   3.3      
Average remaining maturity of foreign currency derivative   Less than twelve months Less than fifteen months                 Within one month Within one month
Cash flow hedge reclassified in to earnings over next twelve months   $ 5.3