Accumulated Other Comprehensive Income (Loss) - Details of Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
BEFORE TAX
Net Change	$ (590.2)	$ 790.8	$ 347.9
TAX EFFECT
Net Change	126.6	(168.1)	(88.9)
AFTER TAX
Net Change	(463.6)	622.7	259.0
U.S. Plan \| Pension Plans, Defined Benefit
AFTER TAX
Defined benefit plan, net periodic benefit cost (credit), gain (loss) due to settlement	(27.9)	0.0	0.0
Unrealized Gains (Losses) on Available for Sale Debt Securities
BEFORE TAX
Gains (Losses)	(685.0)	706.8	306.1
Net Change	(721.3)	707.2	307.2
TAX EFFECT
Gains (Losses)	177.5	(179.3)	(78.0)
Net Change	186.6	(179.4)	(78.3)
AFTER TAX
Gains (Losses)	(507.5)	527.5	228.1
Net Change	(534.7)	527.8	228.9
Interest income on debt securities
BEFORE TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	(36.6)	0.0	0.0
TAX EFFECT
Reclassification Adjustment for Losses (Gains) Included in Net Income	9.2	0.0	0.0
AFTER TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	(27.4)	0.0	0.0
Net gains on debt securities
BEFORE TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	0.3	0.4	1.1
TAX EFFECT
Reclassification Adjustment for Losses (Gains) Included in Net Income	(0.1)	(0.1)	(0.3)
AFTER TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	0.2	0.3	0.8
Unrealized (Losses) Gains on Cash Flow Hedges
BEFORE TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	(4.5)	(28.1)	(26.7)
Net Change	1.1	0.8	(10.3)
TAX EFFECT
Reclassification Adjustment for Losses (Gains) Included in Net Income	1.1	7.0	6.6
Net Change	(0.3)	(0.3)	2.6
AFTER TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	(3.4)	(21.1)	(20.1)
Net Change	0.8	0.5	(7.7)
Foreign Currency Adjustments
BEFORE TAX
Net Change	53.4	(7.5)	65.6
TAX EFFECT
Net Change	(42.9)	34.4	(15.7)
AFTER TAX
Net Change	10.5	26.9	49.9
Foreign Currency Translation Adjustments
BEFORE TAX
Net Change	(133.8)	169.1	6.4
TAX EFFECT
Net Change	4.1	(8.3)	(1.6)
AFTER TAX
Net Change	(129.7)	160.8	4.8
Long-Term Intra-Entity Foreign Currency Transaction (Losses) Gains
BEFORE TAX
Net Change	0.6	2.1	(0.5)
TAX EFFECT
Net Change	(0.1)	(0.5)	0.1
AFTER TAX
Net Change	0.5	1.6	(0.4)
Net Investment Hedge Gains (Losses)
BEFORE TAX
Net Change	186.6	(178.7)	59.7
TAX EFFECT
Net Change	(46.9)	43.2	(14.2)
AFTER TAX
Net Change	139.7	(135.5)	45.5
Pension and Other Postretirement Benefit Adjustments
BEFORE TAX
Gains (Losses)	7.9	47.4	(36.8)
Net Change	76.6	90.3	(14.6)
TAX EFFECT
Gains (Losses)	0.2	(12.3)	7.9
Net Change	(16.8)	(22.8)	2.5
AFTER TAX
Gains (Losses)	8.1	35.1	(28.9)
Net Change	59.8	67.5	(12.1)
Amortization of Net Actuarial Loss
BEFORE TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	41.4	42.2	22.4
TAX EFFECT
Reclassification Adjustment for Losses (Gains) Included in Net Income	(10.3)	(10.4)	(5.4)
AFTER TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	31.1	31.8	17.0
Amortization of Prior Service Cost (Credit)
BEFORE TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	(1.0)	(0.1)	(0.2)
TAX EFFECT
Reclassification Adjustment for Losses (Gains) Included in Net Income	0.3	0.0	0.0
AFTER TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	(0.7)	(0.1)	(0.2)
Settlement Loss
BEFORE TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	28.3	0.8	0.0
TAX EFFECT
Reclassification Adjustment for Losses (Gains) Included in Net Income	(7.0)	(0.1)	0.0
AFTER TAX
Reclassification Adjustment for Losses (Gains) Included in Net Income	21.3	0.7	0.0
Foreign Exchange Contracts \| Unrealized (Losses) Gains on Cash Flow Hedges
BEFORE TAX
Gains (Losses)	5.6	28.9	14.9
TAX EFFECT
Gains (Losses)	(1.4)	(7.3)	(3.7)
AFTER TAX
Gains (Losses)	4.2	21.6	11.2
Interest Rate Contracts \| Unrealized (Losses) Gains on Cash Flow Hedges
BEFORE TAX
Gains (Losses)	0.0	0.0	1.5
TAX EFFECT
Gains (Losses)	0.0	0.0	(0.3)
AFTER TAX
Gains (Losses)	$ 0.0	$ 0.0	$ 1.2

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