Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Statement of Cash Flows [Abstract]
Cash and cash equivalents at beginning of year	$ 746,724	$ 613,110
Cash flows from operating activities:
Net income	563,906	227,393
Adjustments to reconcile net income to cash flows from operating activities:
Depreciation and amortization	123,683	111,535
Gain (Loss) on Disposition of Business	(429,408)	0
Stock-based compensation and other	8,425	9,765
Equity in net income of unconsolidated investments (net of tax)	(34,509)	(57,718)
Dividends received from unconsolidated investments and nonmarketable securities	27,420	12,984
Pension and postretirement benefit	(8,465)	(3,312)
Pension and postretirement contributions	(20,266)	(6,692)
Unrealized gain on investments in marketable securities	(2,384)	(1,278)
Loss on early extinguishment of debt	28,955	0
Deferred income taxes	27,708	8,990
Working capital changes	7,942	(156,579)
Non-cash transfer of 40% value of construction in progress of Kemerton plant to MRL	96,185	87,750
Other, net	(3,339)	(24,921)
Net cash provided by operating activities	385,853	207,917
Cash flows from investing activities:
Acquisitions, net of cash acquired	0	(22,572)
Capital expenditures	(396,915)	(418,991)
Proceeds from Divestiture of Businesses, Net of Cash Divested	290,467	0
Sales of marketable securities, net	4,553	1,496
Investments in equity and other corporate investments	(286)	(486)
Net cash used in investing activities	(102,181)	(440,553)
Cash flows from financing activities:
Proceeds from issuance of common stock	1,453,888	0
Repayments of long-term debt and credit agreements	(1,173,823)	0
Proceeds from borrowings of credit agreements	0	452,163
-325316000	(325,316)	12,956
Fees related to early extinguishment of debt	(24,877)	0
Dividends paid to shareholders	(86,637)	(79,909)
Dividends paid to noncontrolling interests	(43,698)	(14,286)
Proceeds from exercise of stock options	14,335	10,809
Withholding taxes paid on stock-based compensation award distributions	(7,047)	(4,019)
Other	(1,359)	(2,669)
Net cash (used in) provided by financing activities	(194,534)	375,045
Net effect of foreign exchange on cash and cash equivalents	(12,290)	(18,823)
Increase in cash and cash equivalents	76,848	123,586
Cash and cash equivalents at end of period	$ 823,572	$ 736,696