Consolidated Statements of Equity - USD ($) $ in Thousands	Total		Common Shares	Additional Paid-in Capital	Treasury Shares	Accumulated Other Comprehensive Loss	Retained Earnings	Noncontrolling Interests
Beginning Balance at Dec. 31, 2014	$ 824,049		$ 96	$ 222,789	$ (9,743)	$ (54,595)	$ 644,556	$ 20,946
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(11,322)						(13,067)	1,745
Other comprehensive loss	33,656	[1]				33,656
Cash distributions to noncontrolling interest	(3,206)							(3,206)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax of ($819 (187 shares) in 2015, $458 (196 shares) in 2016 and $323 (138 shares) in 2017	1,548			(4,382)	5,930
Purchase of treasury shares (1,193 shares in 2015)	(49,089)				(49,089)
Dividends declared ($0.575 in 2015, $0.625 in 2016 and $0.645 in 2017 per share)	(16,200)						(16,200)
Shares issued for acquisitions (77 shares)	4,303			4,303
Stock award dividend equivalents	0			138			(138)
Ending Balance at Dec. 31, 2015	783,739		96	222,848	(52,902)	(20,939)	615,151	19,485
Increase (Decrease) in Stockholders' Equity
Net income (loss)	14,470						11,594	2,876
Other comprehensive loss	8,471	[1]				8,471
Cash distributions to noncontrolling interest	(5,853)							(5,853)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax of ($819 (187 shares) in 2015, $458 (196 shares) in 2016 and $323 (138 shares) in 2017	7,556			67	7,489
Dividends declared ($0.575 in 2015, $0.625 in 2016 and $0.645 in 2017 per share)	(17,514)						(17,514)
Stock award dividend equivalents	0			(5)	30		(25)
Other changes in noncontrolling interest	(172)
Ending Balance at Dec. 31, 2016	790,697		96	222,910	(45,383)	(12,468)	609,206	16,336
Increase (Decrease) in Stockholders' Equity
Net income (loss)	42,609						42,511	98
Other comprehensive loss	9,768	[1]				9,768
Cash distributions to noncontrolling interest	(377)							(377)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax of ($819 (187 shares) in 2015, $458 (196 shares) in 2016 and $323 (138 shares) in 2017	6,714			1,707	5,007
Dividends declared ($0.575 in 2015, $0.625 in 2016 and $0.645 in 2017 per share)	(18,152)						(18,152)
Stock award dividend equivalents	0			5	64		(69)
Other changes in noncontrolling interest	(8,360)							(8,360)
Ending Balance at Dec. 31, 2017	$ 822,899		$ 96	$ 224,622	$ (40,312)	$ (2,700)	$ 633,496	$ 7,697

[1] All amounts are net of tax. Amounts in parentheses indicate debits