Capital Stock, Accumulated Other Comprehensive Loss and Equity - Summary of Changes in Accumulated Other Comprehensive Loss, Net of Tax (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	$ 4,360.6	$ 4,292.6	$ 3,192.9
Balance at end of year	4,501.1	4,360.6	4,292.6
Defined benefit plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(172.8)	(184.0)	(192.8)
Reclassification adjustments (net of tax expense/benefit)	5.0	9.0	4.9
Other comprehensive income (loss) recognized during the period	(49.8)	2.2	3.9
Balance at end of year	(217.6)	(172.8)	(184.0)
Comprehensive income (loss), tax
Reclassification adjustments, tax expense (benefit)	2.0	2.4	1.1
Other comprehensive income (loss), tax expense (benefit)	(15.7)	0.6	0.4
Derivative instruments and hedging activities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(9.7)
Reclassification adjustments (net of tax expense/benefit)	(38.0)
Other comprehensive income (loss) recognized during the period	57.5
Balance at end of year	9.8	(9.7)
Comprehensive income (loss), tax
Reclassification adjustments, tax expense (benefit)	(10.2)	(4.1)	3.1
Other comprehensive income (loss), tax expense (benefit)	15.7	7.4	12.8
Derivative Instruments and Hedge Activities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(9.7)	(22.9)	(45.1)
Reclassification adjustments (net of tax expense/benefit)		(15.2)	6.4
Other comprehensive income (loss) recognized during the period		28.4	15.8
Balance at end of year		(9.7)	(22.9)
Cumulative translation adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(523.3)	(306.5)	(597.7)
Other comprehensive income (loss) recognized during the period	(41.6)	(216.8)	291.2
Balance at end of year	(564.9)	(523.3)	(306.5)
Comprehensive income (loss), tax
Other comprehensive income (loss), tax expense (benefit)	$ (0.9)	$ (2.3)	$ 0.0