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, 2013	$ 724,421		$ 96	$ 184,380	$ (10,222)	$ (21,181)	$ 548,401	$ 22,947
Increase (Decrease) in Stockholders' Equity
Net income (loss)	122,645						109,726	12,919
Other comprehensive loss	(33,414)	[1]				(33,414)
Cash distributions to noncontrolling interest	(14,920)							(14,920)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax of ($1,485 (219 shares) in 2014, $819 (187 shares) in 2015 and $458 (196 shares) in 2016)	8,662			7,282	1,380
Purchase of treasury shares (17 shares in 2015 and 1,193 shares in 2014)	(901)				(901)
Payment of cash in lieu for stock split (187 shares in 2014)	(58)			(58)
Dividends declared ($0.625 in 2016, $0.575 in 2015 and $0.47 in 2014)	(13,436)						(13,436)
Shares issued for acquisitions (77 shares in 2015 and 556 shares in 2014)	31,050			31,050
Stock award dividend equivalents	0			135			(135)
Ending 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 ($1,485 (219 shares) in 2014, $819 (187 shares) in 2015 and $458 (196 shares) in 2016)	1,548			(4,382)	5,930
Purchase of treasury shares (17 shares in 2015 and 1,193 shares in 2014)	(49,089)				(49,089)
Dividends declared ($0.625 in 2016, $0.575 in 2015 and $0.47 in 2014)	(16,200)						(16,200)
Shares issued for acquisitions (77 shares in 2015 and 556 shares in 2014)	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)
Other changes in noncontrolling interest	172							172
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax of ($1,485 (219 shares) in 2014, $819 (187 shares) in 2015 and $458 (196 shares) in 2016)	7,556			67	7,489
Dividends declared ($0.625 in 2016, $0.575 in 2015 and $0.47 in 2014)	(17,514)						(17,514)
Stock award dividend equivalents	0			(5)	30		(25)
Ending Balance at Dec. 31, 2016	$ 790,697		$ 96	$ 222,910	$ (45,383)	$ (12,468)	$ 609,206	$ 16,336

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