Pension and Other Postretirement Benefit Plans - Pension Plan Assets by Asset Category (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	$ 412.6	$ 522.1	$ 519.2
Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	367.1	368.2	$ 415.1
Fair value, measurements, recurring | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value, excluding alternative investments	359.5	469.1
Alternative investments	53.1	53.0
Assets at fair value	412.6	522.1
Fair value, measurements, recurring | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value, excluding alternative investments	333.9	334.2
Alternative investments	33.2	34.0
Assets at fair value	367.1	368.2
Fair value, measurements, recurring | Mutual funds/Equity funds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	137.7	189.7
Fair value, measurements, recurring | Mutual funds/Equity funds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	132.6	129.8
Fair value, measurements, recurring | Common stock | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	77.5	112.4
Fair value, measurements, recurring | Common stock | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	73.2	70.2
Fair value, measurements, recurring | Mutual funds/Fixed income funds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	86.5	87.8
Fair value, measurements, recurring | Mutual funds/Fixed income funds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	31.2	33.1
Fair value, measurements, recurring | Corporate bonds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	18.1	22.1
Fair value, measurements, recurring | Corporate bonds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	37.1	40.2
Fair value, measurements, recurring | Government obligations | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	29.9	18.8
Fair value, measurements, recurring | Government obligations | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	53.8	55.5
Fair value, measurements, recurring | Preferred stock | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	1.4	2.2
Fair value, measurements, recurring | Cash and short-term investments | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	8.4	36.1
Fair value, measurements, recurring | Cash and short-term investments | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	6.0	5.4
Level 1 | Fair value, measurements, recurring | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	277.1	387.5
Level 1 | Fair value, measurements, recurring | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	134.6	134.1
Level 1 | Fair value, measurements, recurring | Mutual funds/Equity funds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	137.7	189.7
Level 1 | Fair value, measurements, recurring | Mutual funds/Equity funds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	27.0	28.0
Level 1 | Fair value, measurements, recurring | Common stock | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	51.1	72.5
Level 1 | Fair value, measurements, recurring | Common stock | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	73.2	70.2
Level 1 | Fair value, measurements, recurring | Mutual funds/Fixed income funds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	86.5	87.8
Level 1 | Fair value, measurements, recurring | Mutual funds/Fixed income funds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	31.2	33.1
Level 1 | Fair value, measurements, recurring | Corporate bonds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 1 | Fair value, measurements, recurring | Corporate bonds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 1 | Fair value, measurements, recurring | Government obligations | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 1 | Fair value, measurements, recurring | Government obligations | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 1 | Fair value, measurements, recurring | Preferred stock | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.9	1.4
Level 1 | Fair value, measurements, recurring | Cash and short-term investments | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.9	36.1
Level 1 | Fair value, measurements, recurring | Cash and short-term investments | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	3.2	2.8
Level 2 | Fair value, measurements, recurring | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	82.4	81.6
Level 2 | Fair value, measurements, recurring | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	199.3	200.1
Level 2 | Fair value, measurements, recurring | Mutual funds/Equity funds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 2 | Fair value, measurements, recurring | Mutual funds/Equity funds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	105.6	101.8
Level 2 | Fair value, measurements, recurring | Common stock | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	26.4	39.9
Level 2 | Fair value, measurements, recurring | Common stock | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 2 | Fair value, measurements, recurring | Mutual funds/Fixed income funds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 2 | Fair value, measurements, recurring | Mutual funds/Fixed income funds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 2 | Fair value, measurements, recurring | Corporate bonds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	18.1	22.1
Level 2 | Fair value, measurements, recurring | Corporate bonds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	37.1	40.2
Level 2 | Fair value, measurements, recurring | Government obligations | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	29.9	18.8
Level 2 | Fair value, measurements, recurring | Government obligations | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	53.8	55.5
Level 2 | Fair value, measurements, recurring | Preferred stock | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.5	0.8
Level 2 | Fair value, measurements, recurring | Cash and short-term investments | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	7.5	0.0
Level 2 | Fair value, measurements, recurring | Cash and short-term investments | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	2.8	2.6
Level 3 | Fair value, measurements, recurring | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Mutual funds/Equity funds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Mutual funds/Equity funds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Common stock | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Common stock | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Mutual funds/Fixed income funds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Mutual funds/Fixed income funds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Corporate bonds | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Corporate bonds | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Government obligations | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Government obligations | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Preferred stock | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Cash and short-term investments | U.S. Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	0.0	0.0
Level 3 | Fair value, measurements, recurring | Cash and short-term investments | Foreign Pension
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	$ 0.0	$ 0.0