Condensed Consolidated Statements of Equity (Unaudited) (USD $) In Thousands, unless otherwise specified	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 [Roll Forward]
Net income (loss)	26,029						22,708	3,321
Other comprehensive (loss)	(2,976)	[1]				(2,976)
Cash distributions to noncontrolling interest	(2,451)							(2,451)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax of $216 (162 shares) and $1,530 (214 shares) for the period Marc 31, 2015 and 2014, respectively	1,490			18	1,472
Payment of cash in lieu for stock split (187 shares)	(58)			(58)
Dividends declared ($0.14 and $0.11 per common share for the year Marc 31, 2015 and 2014, respectively)	(3,126)						(3,126)
Performance share unit dividend equivalents	0			134			(134)
Ending Balance at Mar. 31, 2014	743,329		96	184,474	(8,750)	(24,157)	567,849	23,817
Beginning Balance at Dec. 31, 2014	824,049		96	222,789	(9,743)	(54,595)	644,556	20,946
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	3,945						4,097	(152)
Other comprehensive (loss)	(3,535)	[1]				(3,535)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax of $216 (162 shares) and $1,530 (214 shares) for the period Marc 31, 2015 and 2014, respectively	924			(4,051)	4,975
Purchase of treasury shares (631 shares)	(27,783)				(27,783)
Dividends declared ($0.14 and $0.11 per common share for the year Marc 31, 2015 and 2014, respectively)	(3,985)						(3,985)
Shares issued for acquisitions (77 shares)	4,303			4,303
Performance share unit dividend equivalents	0			138			(138)
Ending Balance at Mar. 31, 2015	$ 797,918		$ 96	$ 223,179	$ (32,551)	$ (58,130)	$ 644,530	$ 20,794

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