Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2017	[1]	Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[2]	Sep. 30, 2016	[2]	Jun. 30, 2016	[2]	Mar. 31, 2016	[2]	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Rationalization charges	$ 1,300		$ 600		$ 3,000		$ 900		$ 5,100		$ 7,800		$ 5,000		$ 1,100		$ 5,826	$ 19,061	$ 14,407
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost																	13,372	12,895	15,562
Interest cost																	25,501	25,781	28,066
Expected return on plan assets																	(63,010)	(58,504)	(62,726)
Amortization of prior service cost (credit)																	313	561	1,037
Amortization of actuarial losses (gains)																	7,077	8,573	5,556
Special termination benefits																	0	2,837	0
Curtailment loss (gain)																	0	183	(522)
Net periodic benefit credit																	(16,747)	(7,674)	(13,027)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost																	104	222	444
Interest cost																	692	891	1,281
Expected return on plan assets																	0	0	0
Amortization of prior service cost (credit)																	(3,418)	(3,571)	(3,057)
Amortization of actuarial losses (gains)																	(596)	(599)	(348)
Special termination benefits																	0	0
Curtailment loss (gain)																	0	(823)	0
Net periodic benefit credit																	(3,218)	(3,880)	(1,680)
Special Termination Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Rationalization charges																	$ 0	2,197	$ (522)
LaPorte, Indiana manufacturing facility [Member] | Special Termination Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Rationalization charges																		2,800
LaPorte, Indiana manufacturing facility [Member] | Net Curtailment Gain [Member]
Defined Benefit Plan Disclosure [Line Items]
Rationalization charges																		$ (600)

[1] The first, second, third and fourth quarters of 2017 include rationalization charges of $0.9 million, $3.0 million, $0.6 million and $1.3 million, respectively. The first, second, third and fourth quarters of 2017 includes costs attributed to announced acquisitions of $13.2 million, $9.8 million, $0.8 million and $0.9 million, respectively. The first and second quarters of 2017 include a loss on early extinguishment of debt of $2.7 million and $4.4 million, respectively. The fourth quarter of 2017 includes the benefit from effective tax rate adjustments totaling $110.9 million primarily related to the remeasurement of net deferred tax liabilities to reflect the lower future cash tax obligations as a result of the reduction in the federal corporate tax rate under the 2017 Tax Act.

[2] The first, second, third and fourth quarters of 2016 include rationalization charges of $1.1 million, $5.0 million, $7.8 million and $5.1 million, respectively. The fourth quarter of 2016 includes costs attributed to announced acquisitions of $1.4 million.