Schedule of Borrowings (Parenthetical) (Detail)	Mar. 31, 2013	Dec. 31, 2012
4.2% Senior Notes
Debt Instrument [Line Items]
Senior Notes, maturity date	2021-12	2021-12
4.5 % Senior Notes
Debt Instrument [Line Items]
Senior Notes, maturity date	2020-12	2020-12
2.58% Senior Euro Notes
Debt Instrument [Line Items]
Senior Notes, maturity date	2015-06	2015-06