EQUITY ROLL FORWARD (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance			$ 598,216
Net income	27,458	28,439	44,879	44,054
Equity, ending balance	640,461		640,461
Common Stock
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance			4,771
Common stock issued			6
Common stock repurchased or received for stock options exercised			(16)
Share-based compensation			(1)
Equity, ending balance	4,760		4,760
Additional Paid in Capital
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance			194,810
Common stock issued			1,178
Share-based compensation			5,077
Tax benefit of stock options exercised			1,469
Equity, ending balance	202,534		202,534
Retained Earnings
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance			450,855
Net income			44,031
Adjustment to Impo redemption value			(235)
Dividends on common stock			(8,017)
Common stock repurchased or received for stock options exercised			(6,459)
Equity, ending balance	480,175		480,175
Minimum Pension Liability
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance			(38,707)
Pension liability, net of tax			976
Equity, ending balance	(37,731)		(37,731)
Cumulative Translation Adjustment
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance			(16,022)
Currency translation adjustment			4,681
Equity, ending balance	(11,341)		(11,341)
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance			2,509
Net income			382
Noncontrolling dividend			(800)
Currency translation adjustment			(27)
Equity, ending balance	2,064		2,064
Total Equity
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance			598,216
Net income			44,413
Adjustment to Impo redemption value			(235)
Dividends on common stock			(8,017)
Common stock issued			1,184
Common stock repurchased or received for stock options exercised			(6,475)
Share-based compensation			5,076
Tax benefit of stock options exercised			1,469
Noncontrolling dividend			(800)
Currency translation adjustment			4,654
Pension liability, net of tax			976
Equity, ending balance	640,461		640,461
Redeemable Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity
Equity, beginning balance			5,171
Net income			466
Adjustment to Impo redemption value			235
Impo acquisition			(2,875)
Currency translation adjustment			25
Equity, ending balance	$ 3,022		$ 3,022