Cash and Investments - Schedule of Interest Income and Dividends (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Interest income:
Cash and short term investments	$ 158.1	$ 117.5
Bonds	555.0	441.9
Derivatives and other	30.8	(44.8)
Interest income	743.9	514.6
Dividends:
Dividend income	81.5	73.2
Investment expenses	(41.9)	(28.8)
Interest and dividends	783.5	559.0
Share of profit of associates	221.1	200.5
Preferred stocks
Dividends:
Dividend income	11.0	2.1
Common stocks
Dividends:
Dividend income	70.5	71.1
Investments in associates
Dividends:
Share of profit of associates	221.1	200.5
Impairment charges recorded in share of profit of associates	$ (57.3)	$ (46.6)

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Interest Income [Abstract]

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No definition available.

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The amount of fee income and expense (other than the amounts included when determining the effective interest rate) arising from trust and other fiduciary activities that result in the holding or investing of assets on behalf of individuals, trusts, retirement benefit plans and other institutions.

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The amount of impairment loss recognised in profit or loss. [Refer: Impairment loss; Profit (loss)]

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The amount of interest income on cash and cash equivalents. [Refer: Interest income; Cash and cash equivalents]

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The amount of interest income on debt instruments held. [Refer: Interest income; Debt instruments held]

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The amount of interest income on other financial assets. [Refer: Interest income; Other financial assets]

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The amount of investment income, such as interest and dividends.

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The amount of dividends recognised as income. Dividends are distributions of profits to holders of equity investments in proportion to their holdings of a particular class of capital.

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The amount of income arising from interest.

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The entity's share of the profit (loss) of associates accounted for using the equity method. [Refer: Associates [member]; Investments accounted for using equity method; Profit (loss)]

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