SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Adoption of ASU 2017-07 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of sales	$ 1,818,398	$ 1,812,961	$ 1,603,070
Selling, research & development and administrative	454,617	429,955	387,424
Total Operating Expenses	2,488,039	2,478,492	2,145,796
Operating Income	371,693	286,269	323,487
Miscellaneous, net	1,556	5,550	6,694
Total Other (Expense) Income	(29,624)	(20,249)	(28,662)
Income before Income Taxes	$ 342,069	266,020	$ 294,825
Accounting Standards Update 2018-02 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of accounting standards		6,658
Accounting Standards Update 2018-02 | Accumulated Other Comprehensive Income/(Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of accounting standards		$ (6,658)