Pension and Other Postretirement Benefits - Net Periodic Pension and Other Postretirement Benefit Costs (Detail) - USD ($) $ in Thousands		1 Months Ended	6 Months Ended	12 Months Ended
	Jun. 01, 2018	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Curtailment loss (gain)	$ 21
Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Effect of plan amendment				$ 236
Curtailment loss (gain)		$ 1,641
Defined Benefit Pension Plan [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost				633	$ 1,225
Interest cost				9,018	8,473
Expected return on plan assets				(12,623)	(13,282)
Amortization of prior service cost (credit)				64	44
Actuarial loss (gain)				1,153	1,471
Effect of plan amendment				236	0
Special termination benefits				3,694	1,350
Curtailment loss (gain)				1,641	21
Total net periodic pension and other postretirement benefit costs				3,816	(698)
Defined Benefit Pension Plan [Member] | Foreign Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost				444	477
Interest cost				1,399	1,391
Expected return on plan assets				(2,321)	(2,580)
Amortization of prior service cost (credit)				(284)	(336)
Actuarial loss (gain)				669	727
Effect of plan amendment				0	0
Special termination benefits				0	0
Curtailment loss (gain)				0	0
Total net periodic pension and other postretirement benefit costs				(93)	(321)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost				286	457
Interest cost				390	494
Expected return on plan assets				0	0
Amortization of prior service cost (credit)				(1,804)	(1,607)
Actuarial loss (gain)				(336)	(231)
Effect of plan amendment				0	0
Special termination benefits				0	126
Curtailment loss (gain)		$ (7,639)	$ (15)	(7,654)	0
Total net periodic pension and other postretirement benefit costs				$ (9,118)	$ (761)