Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Undistributed foreign pre-tax earnings	$ 364.1
Cash proceeds from the sale of Trayport	603.9
Accrued tax liabilities foreign earnings	135.5
Effective cash taxes, amount	64.0
Unrecognized tax benefits	1.6	$ 1.6
Accrued interest related to uncertain tax positions	$ 0.2
Accrued interest and penalties related to uncertain tax positions		$ 0.2

Amount of deferred tax liability attributable to taxable temporary differences from undistributed earnings of subsidiaries and other recognized entities not within the country of domicile of the entity.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to repatriation of foreign earnings.

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The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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Amount of undistributed earnings of foreign subsidiaries intended to be permanently reinvested outside the country of domicile.

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of interest expense accrued for an underpayment of income taxes.

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