Investments in Affiliated Companies (Detail) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Equity Method Investments	$ 42.5	$ 46.1
Cost Method investments	219.4	192.6
Limited Partnership Investment	2.5	1.8
Total investments in affiliated companies (Note 6)	$ 264.4	$ 240.5

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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