Pension and Other Employee Benefits - Reconciliation of Benefit Obligation, Fair Value of Plan Assets and Funded Status of Respective Defined Benefit (Pension) and Postretirement Benefit Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in plan assets:
Employer contributions	$ 2,800	$ 4,000	$ 4,000
Amounts recognized in the balance sheet consist of:
Total 'Non-current liabilities	23,691	8,328
US Pension Benefits [Member]
Change in benefit obligation:
Obligation at beginning of period	26,188	26,242
Assumed Stromag benefit obligation	0	0
Service cost	3	0
Interest cost	1,016	987
Partial settlement payments	0	0
Actuarial (gains) losses	530	79
Foreign exchange effect	0	0
Benefits paid	(2,093)	(1,120)
Obligation at end of period	25,644	26,188	26,242
Change in plan assets:
Fair value of plan assets, beginning of period	25,432	24,558
Partial settlement payments	0	0
Actual return on plan assets	1,765	(555)
Employer contributions	0	2,738
Plan expenses	(173)	(189)
Benefits paid	(2,093)	(1,120)
Fair value of plan assets, end of period	24,931	25,432	24,558
Funded status	713	756
Amounts recognized in the balance sheet consist of:
Total 'Non-current liabilities	713	756
Non-US Pension Benefits [Member]
Change in benefit obligation:
Obligation at beginning of period	7,802	8,619
Assumed Stromag benefit obligation	15,284	0
Service cost	92	92
Interest cost	171	181
Partial settlement payments	(149)	0
Actuarial (gains) losses	520	(34)
Foreign exchange effect	(263)	(883)
Benefits paid	(257)	(173)
Obligation at end of period	23,200	7,802	8,619
Change in plan assets:
Fair value of plan assets, beginning of period	230	310
Partial settlement payments	0	0
Actual return on plan assets	8	13
Employer contributions	248	100
Plan expenses	(7)	(20)
Benefits paid	(257)	(173)
Fair value of plan assets, end of period	222	230	310
Funded status	22,978	7,572
Amounts recognized in the balance sheet consist of:
Total 'Non-current liabilities	22,978	7,572
Total Pension Benefits [Member]
Change in benefit obligation:
Obligation at beginning of period	33,990	34,861
Assumed Stromag benefit obligation	15,284	0
Service cost	95	92
Interest cost	1,187	1,168
Partial settlement payments	(149)	0
Actuarial (gains) losses	1,050	45
Foreign exchange effect	(263)	(883)
Benefits paid	(2,350)	(1,293)
Obligation at end of period	48,844	33,990	34,861
Change in plan assets:
Fair value of plan assets, beginning of period	25,662	24,868
Partial settlement payments	0	0
Actual return on plan assets	1,773	(542)
Employer contributions	248	2,838
Plan expenses	(180)	(209)
Benefits paid	(2,350)	(1,293)
Fair value of plan assets, end of period	25,153	25,662	$ 24,868
Funded status	23,691	8,328
Amounts recognized in the balance sheet consist of:
Total 'Non-current liabilities	$ 23,691	$ 8,328