Derivative Instruments and Hedging Activities - Commitment of Cross Currency Swaps (Parenthetical) (Detail) (Floating Rate Receivable [Member])	Dec. 31, 2012
Derivative [Line Items]
LIBOR fixed	1.12%
LIBOR rate receivable cap	3.50%
Currency swaps maturing in 2013 [Member]
Derivative [Line Items]
LIBOR fixed	1.12%
LIBOR rate receivable cap	3.50%

Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract.

No definition available.

Name:	us-gaap_DerivativeCapInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant