CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Capital	Retained Earnings	Accumulated Other Comprehensive Income/(Loss)	Noncontrolling Interest
Balance at Jan. 02, 2016		$ 4,622	$ 216,472	$ 498,214	$ (161,608)	$ 1,765
Balance (in shares) at Jan. 02, 2016		46,219,000
Increase (Decrease) in Stockholders' Equity
Net income				78,745		577
Currency translation adjustment					(8,234)	(26)
Minimum pension liability adjustment, net of tax expense/(benefit) of $307, $534, and $499 for 2018, 2017, and 2016, respectively					(10)
Adjustments to Impo redemption value				(1,002)
Dividends on common stock ($0.4675, $0.4225, and $0.3975 per share for the years of 2018, 2017, and 2016, respectively)				(18,464)
Noncontrolling dividend						(673)
Common stock issued		$ 27	5,216
Common stock issued (in shares)		274,000
Share-based compensation		$ 13	6,876
Share-based compensation (in shares)		125,000
Common stock repurchased	$ (3,800)	$ (24)		(7,398)
Common stock repurchased (in shares)	(144,600)	(242,000)
Balance at Dec. 31, 2016		$ 4,638	228,564	550,095	(169,852)	1,643
Balance (in shares) at Dec. 31, 2016		46,376,000
Temporary equity, beginning balance at Jan. 02, 2016	$ 6,856
Increase (Decrease) in Redeemable Noncontrolling Interest
Net income	(7)
Currency translation adjustment	(199)
Adjustments to Impo redemption value	1,002
Temporary equity, ending balance at Dec. 31, 2016	7,652
Increase (Decrease) in Stockholders' Equity
Net income				78,180		661
Currency translation adjustment					18,601	164
Minimum pension liability adjustment, net of tax expense/(benefit) of $307, $534, and $499 for 2018, 2017, and 2016, respectively					2,204
Adjustments to Impo redemption value				27
Dividends on common stock ($0.4675, $0.4225, and $0.3975 per share for the years of 2018, 2017, and 2016, respectively)				(19,785)
Noncontrolling dividend						(504)
Common stock issued		$ 25	4,472
Common stock issued (in shares)		256,000
Share-based compensation		$ 9	7,100
Share-based compensation (in shares)		86,000
Common stock repurchased	$ 0	$ (9)		(3,612)
Common stock repurchased (in shares)	0	(88,000)
Balance at Dec. 31, 2017	$ 702,621	$ 4,663	240,136	604,905	(149,047)	1,964
Balance (in shares) at Dec. 31, 2017	46,630,000	46,630,000
Increase (Decrease) in Redeemable Noncontrolling Interest
Net income	$ (248)
Currency translation adjustment	(828)
Adjustments to Impo redemption value	(27)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	(5,047)
Temporary equity, ending balance at Dec. 31, 2017	1,502
Increase (Decrease) in Stockholders' Equity
Net income				105,877		701
Currency translation adjustment					(34,751)	(49)
Minimum pension liability adjustment, net of tax expense/(benefit) of $307, $534, and $499 for 2018, 2017, and 2016, respectively					779
Dividends on common stock ($0.4675, $0.4225, and $0.3975 per share for the years of 2018, 2017, and 2016, respectively)				(21,951)
Noncontrolling dividend						(661)
Common stock issued		$ 40	8,959
Common stock issued (in shares)		405,000
Share-based compensation		$ 10	8,440
Share-based compensation (in shares)		103,000
Common stock repurchased	$ (31,400)	$ (81)		(34,107)
Common stock repurchased (in shares)	(749,614)	(812,000)
Balance at Dec. 31, 2018	$ 735,827	$ 4,632	$ 257,535	$ 654,724	$ (183,019)	$ 1,955
Balance (in shares) at Dec. 31, 2018	46,326,000	46,326,000
Increase (Decrease) in Redeemable Noncontrolling Interest
Net income	$ (1,061)
Currency translation adjustment	77
Temporary equity, ending balance at Dec. 31, 2018	$ 518