Summary of Short-Term Borrowings and Long-Term Debt (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Commercial paper issuances	$ 150.0	$ 250.0
Various debt due to international banks	4.0	3.8
Total short-term borrowings	154.0	253.8
Net long-term debt	649.5	649.4
2.875% Senior notes due October 1, 2022
Debt Instrument [Line Items]
Senior notes	400.0	400.0
Less: Discount	(0.3)	(0.4)
3.35% Senior Notes Due December 15, 2015
Debt Instrument [Line Items]
Senior notes	250.0	250.0
Less: Discount	$ (0.2)	$ (0.2)

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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Carrying amount at the balance sheet date of borrowings from a bank, not elsewhere enumerated in the taxonomy, with a maturity within one year (or within one operating cycle if longer) from the date of borrowing.

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