Cash and Cash Equivalents - Cash and Short-Term Investments (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Cash and Cash Equivalents [Abstract]
Interest-bearing deposits at the FRB-NY	$ 219.4	$ 234.0
Money market mutual funds	5.7	26.3
Other	91.7	6.0
Total short-term investments	$ 316.8	$ 266.3

Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant