EQUITY ROLL FORWARD (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Common Stock, Dividends, Per Share, Cash Paid	$ 0.175	$ 0.155
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance	$ 849,949
Net income	28,163	$ 10,792
Equity, ending balance	863,686
Temporary equity, beginning balance	(245)	(236)
Net income	76	(38)
Temporary Equity, Foreign Currency Translation Adjustments	1	29
Temporary equity, ending balance	(168)	(245)
Common Stock
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance	4,622	4,639
Stock Issued During Period, Value, New Issues	14	2
Stock Repurchased and Retired During Period, Value	(6)	(35)
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	11	8
Equity, ending balance	4,641	4,614
Additional Paid in Capital
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance	283,420	269,656
Stock Issued During Period, Value, New Issues	5,069	869
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	4,179	4,344
Equity, ending balance	292,668	274,869
Retained Earnings
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance	764,562	712,460
Net income	27,880	10,643
Dividends, Common Stock, Cash	(8,143)	(7,240)
Stock Repurchased and Retired During Period, Value	(4,843)	(16,946)
Equity, ending balance	779,456	698,917
Minimum Pension Liability
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance	(52,666)	(50,089)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	884	716
Equity, ending balance	(51,782)	(49,373)
Cumulative Translation Adjustment
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance	(152,105)	(140,121)
Currency translation adjustment	(11,449)	(37,727)
Equity, ending balance	(163,554)	(177,848)
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance	2,116	2,124
Net income	207	187
Currency translation adjustment	(66)	(24)
Equity, ending balance	2,257	2,287
Total Equity
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance	849,949	798,669
Net income	28,087	10,830
Dividends, Common Stock, Cash	(8,143)	(7,240)
Stock Issued During Period, Value, New Issues	5,083	871
Stock Repurchased and Retired During Period, Value	(4,849)	(16,981)
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	4,190	4,352
Currency translation adjustment	(11,515)	(37,751)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	884	716
Equity, ending balance	$ 863,686	$ 753,466