CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Cash and cash equivalents at beginning of year	$ 2,269,756	$ 213,734	$ 2,489,768
Cash flows from operating activities:
Net income	99,468	680,769	360,064
Adjustments to reconcile net income to cash flows from operating activities:
Depreciation and amortization	196,928	226,169	260,076
Gain associated with restructuring and other	0	0	(6,804)
Gain on acquisition	(6,221)	0	0
Gain on sales of businesses, net	0	(510,278)	0
Stock-based compensation	19,404	17,031	15,188
Equity in net income of unconsolidated investments (net of tax)	(84,487)	(61,534)	(30,999)
Dividends received from unconsolidated investments and nonmarketable securities	39,386	43,759	59,912
Pension and postretirement (benefit) expense	(12,436)	41,546	(38,817)
Pension and postretirement contributions	(13,341)	(20,068)	(21,613)
Unrealized gain on investments in marketable securities	(3,135)	(3,655)	(1,239)
Loss on early extinguishment of debt	52,801	1,921	5,353
Deferred income taxes	(41,941)	21,121	(136,298)
Changes in current assets and liabilities, net of effects of acquisitions and divestitures:
(Increase) in accounts receivable	(74,545)	(42,816)	(8,788)
(Increase) decrease in inventories	(101,545)	25,974	27,649
(Increase) decrease in other current assets	(213)	1,808	12,756
Increase in accounts payable	53,421	43,953	23,745
(Decrease) increase in accrued expenses and income taxes payable	(269,381)	210,276	(96,896)
Other, net	449,816	59,548	(62,479)
Net cash provided by operating activities	303,979	735,524	360,810
Cash flows from investing activities:
Acquisition of Rockwood, net of cash acquired	0	0	(2,051,645)
Other acquisitions, net of cash acquired	(44,367)	(126,747)	(48,845)
Cash payments related to acquisitions and other	0	(81,987)	0
Capital expenditures	(317,703)	(196,654)	(227,649)
Decrease in restricted cash	0	0	57,550
Cash proceeds from divestitures, net	6,857	3,325,571	8,883
Return of capital from unconsolidated investment	0	0	98,000
(Investments in) sales of marketable securities, net	(275)	305	998
Repayments from joint ventures	1,250	0	2,156
Investments in equity and other corporate investments	(3,565)	0	0
Net cash (used in) provided by investing activities	(357,803)	2,920,488	(2,160,552)
Cash flows from financing activities:
Proceeds from borrowings of other long-term debt	27,000	0	2,250,000
Repayments of long-term debt	(778,209)	(1,252,302)	(2,582,901)
Other borrowings (repayments), net	138,751	(163,721)	54,625
Fees related to early extinguishment of debt	(46,959)	0	(43,340)
Dividends paid to shareholders	(140,557)	(135,353)	(119,302)
Dividends paid to noncontrolling interests	(36,756)	(35,855)	(23,286)
Purchase of noncontrolling interest	0	0	(4,784)
Repurchases of common stock	(250,000)	0	0
Proceeds from exercise of stock options	8,238	9,401	517
Withholding taxes paid on stock-based compensation award distributions	(8,376)	(2,194)	(1,549)
Debt financing costs	0	0	(4,544)
Other	0	0	(3,882)
Net cash used in financing activities	(1,086,868)	(1,580,024)	(478,446)
Net effect of foreign exchange on cash and cash equivalents	8,239	(19,966)	2,154
(Decrease) increase in cash and cash equivalents	(1,132,453)	2,056,022	(2,276,034)
Cash and cash equivalents at end of year	$ 1,137,303	$ 2,269,756	$ 213,734