Debt - Outstanding Debt (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Commercial paper	$ 84.2	$ 114.4
Short-term loans	0.0
Current maturities of long-term debt and finance leases	2.3	1.8
Commercial paper and current maturities of long-term debt	86.5	116.2
Long-term debt and finance leases	12.9	8.8
Total debt and finance leases	$ 99.4	$ 125.0

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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13)(2))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 944
-SubTopic 210
-Section S99
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-Subparagraph (SX 210.7-03(a)(16))
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of short-term and long-term debt and lease obligation.

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Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of long-term debt and lease obligation, classified as noncurrent.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of borrowings classified as other, maturing within one year or the normal operating cycle, if longer.

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