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Business Combinations - Summary of Unaudited Pro Forma Historical Results (Detail) - USD ($) $ / shares in Units, $ in Millions | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018
Business Combinations [Abstract] |  |
Total revenues | $ 7,390.5 | $ 7,383.1
Net earnings attributable to controlling interests | $ 669.1 | $ 659.3
Basic earnings per share | $ 3.57 | $ 3.57
Diluted earnings per share | $ 3.50 | $ 3.51

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