Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands			12 Months Ended
	Oct. 31, 2019	Jan. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Summary Of Significant Accounting Policies [Line Items]
Trade accounts receivable arising from contracts with customers			$ 602,100	$ 590,300
Operating lease, right-of-use asset			133,864	$ 0
Operating lease, lease liability			$ 137,823
Reduction in federal statutory rate		21.00%	21.00%	21.00%	35.00%
Foreign exchange transaction losses			$ (27,400)	$ (10,500)	$ (11,100)
Maximum remaining expiration period for foreign currency forward contracts			1 year
Minimum
Summary Of Significant Accounting Policies [Line Items]
Payment terms			30 days
Timing between shipment and delivery			1 day
Property, plant and equipment, useful life			2 years
Finite-lived intangible assets, useful life			5 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Payment terms			90 days
Timing between shipment and delivery			45 days
Property, plant and equipment, useful life			60 years
Finite-lived intangible assets, useful life			25 years
Planned Major Maintenance Activities
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			12 months
Accounting Standards Update 2016-02
Summary Of Significant Accounting Policies [Line Items]
Operating lease, right-of-use asset						$ 139,100
Operating lease, lease liability						$ 139,100
Mineral Resources Limited Wodgina Project
Summary Of Significant Accounting Policies [Line Items]
Interest percentage acquired	60.00%
Ownership percentage	60.00%		60.00%