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Effect of New Accounting Pronouncements - Additional Information (Detail) - USD ($) $ in Millions |  | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jan. 01, 2016 | Jun. 30, 2018 | Jun. 30, 2017 | [1] | Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |
Corporate income tax rate |  | 21.00% |  | 35.00%
Net cash provided by operating activities |  | $ 313.3 | $ 260.9 |
Effect of changes in foreign exchange rates on cash, cash equivalents and restricted cash |  | (29.5) | $ 34.8 |
Accounting Standards Update 2016-18 [Member] |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |
Net cash provided by operating activities |  |  |  | $ 55.5
Cash paid for acquisitions, net of cash and restricted cash |  |  |  | 11.1
Effect of changes in foreign exchange rates on cash, cash equivalents and restricted cash |  |  |  | $ 22.4
Accounting Standards Update 2014-09 [Member] |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |
Cumulative effect of adoption recognized as an increase to retained earnings | $ 125.3 |  |  |
Accounting Standards Update 2018-02 [Member] |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |
Increase in retained earnings |  | $ 6.6 |  |
[1] | See Note 3 - Revenues from Contracts with Customers for additional information about the restatements related to ASC 606.

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