SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES – Adoption of ASU 2017-07 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of sales	$ 1,812,961	$ 1,603,070	$ 1,496,174
Selling, research & development and administrative	429,955	387,424	366,269
Total Operating Expenses	2,478,492	2,145,796	2,017,245
Operating Income	286,269	323,487	313,689
Miscellaneous, net	5,550	6,694	(407)
Total Other (Expense) Income	(20,249)	(28,662)	(33,192)
Income before Income Taxes	266,020	294,825	280,497
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)
Original Balance | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of sales		1,604,181	1,498,070
Selling, research & development and administrative		388,281	367,562
Total Operating Expenses		2,147,764	2,020,434
Operating Income		321,519	310,500
Miscellaneous, net		8,662	2,782
Total Other (Expense) Income		(26,694)	(30,003)
Income before Income Taxes		294,825	280,497
Adjustment | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of sales		(1,111)	(1,896)
Selling, research & development and administrative		(857)	(1,293)
Total Operating Expenses		(1,968)	(3,189)
Operating Income		1,968	3,189
Miscellaneous, net		(1,968)	(3,189)
Total Other (Expense) Income		$ (1,968)	$ (3,189)