Employee Benefits - Plan Assets and Benefit Obligations of Defined Benefit Pension Plans (Detail) - Pension Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	$ 2,175	$ 2,497	$ 3,144
Interest cost on projected benefit obligation	20,075	24,096	23,705
Expected return on plan assets	(35,577)	(33,988)	(32,405)
Net amortization of deferrals	5,424	5,821	21,390
Settlements and curtailments	0	0	0
Net periodic benefit cost	(7,903)	(1,574)	15,834
Defined contribution and other retirement plans	8,604	8,404	7,104
Total expense	701	6,830	22,938
Net actuarial loss (gain)	(12,145)	(4,917)
Recognized actuarial loss	(5,383)	(5,759)
Prior service cost	93	0
Recognized prior service (cost) credit	(41)	(62)
Currency translation adjustment	0	0
Total recognized in OCI (before tax effects)	(17,476)	(10,738)
Non-U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	18,652	15,210	15,866
Interest cost on projected benefit obligation	17,116	24,413	25,389
Expected return on plan assets	(50,626)	(45,865)	(50,437)
Net amortization of deferrals	14,403	12,802	12,864
Settlements and curtailments	2,746	0	0
Net periodic benefit cost	2,291	6,560	3,682
Defined contribution and other retirement plans	5,681	6,304	7,028
Total expense	7,972	12,864	$ 10,710
Net actuarial loss (gain)	(20,557)	72,848
Recognized actuarial loss	(17,895)	(13,643)
Prior service cost	0	0
Recognized prior service (cost) credit	747	742
Currency translation adjustment	36,722	(43,270)
Total recognized in OCI (before tax effects)	$ (983)	$ 16,677