Fair Value of Cross Currency Basis Swaps that are Designated as Hedges of Net Investments in Foreign Operations (Parenthetical) (Detail)	Dec. 31, 2011 Currency, Swiss Franc	Dec. 31, 2011 Currency, Euro	Dec. 31, 2011 Cross Currency Basis Swaps USD ($)	Dec. 31, 2011 Cross Currency Basis Swaps CHF	Dec. 31, 2011 Cross Currency Basis Swaps EUR (€)	Dec. 31, 2011 Cross Currency Basis Swaps Currency, Euro
Derivative Instruments, Gain (Loss) [Line Items]
Forward contract amounts			$ 449,800,000.0	592,500,000	€ 618,000,000
Forward exchange rate to U.S. Dollars	1.12	1.27				1.45