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, 2012	$ 611,445		$ 96	$ 181,627	$ (12,559)	$ (45,379)	$ 470,628	$ 17,032
Increase (Decrease) in Stockholders' Equity
Net income (loss)	95,702						89,939	5,763
Other comprehensive income (loss)	24,198	[1]				24,198
Proceeds received from noncontrolling investor owner	152							152
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax	5,035			2,698	2,337
Dividends declared ($0.575 in 2015, $0.47 in 2014 and $0.43 in 2013)	(12,111)						(12,111)
Performance share unit dividends equivalents	0			55			(55)
Ending 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 income (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	8,662			7,282	1,380
Purchase of treasury shares (1,193 in 2015 and 17 in 2014)	(901)				(901)
Payment of cash in lieu for stock split (187 shares)	(58)			(58)
Dividends declared ($0.575 in 2015, $0.47 in 2014 and $0.43 in 2013)	(13,436)						(13,436)
Shares issued for acquisitions (77 shares in 2015 and 556 shares in 2014)	31,050			31,050
Performance share unit dividends 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 income (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	1,548			(4,382)	5,930
Purchase of treasury shares (1,193 in 2015 and 17 in 2014)	(49,089)				(49,089)
Dividends declared ($0.575 in 2015, $0.47 in 2014 and $0.43 in 2013)	(16,200)						(16,200)
Shares issued for acquisitions (77 shares in 2015 and 556 shares in 2014)	4,303			4,303
Performance share unit dividends equivalents	0			138			(138)
Ending Balance at Dec. 31, 2015	$ 783,739		$ 96	$ 222,848	$ (52,902)	$ (20,939)	$ 615,151	$ 19,485

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