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, 2012	$ 611,445		$ 96	$ 181,627	$ (12,559)	$ (45,379)	$ 470,628	$ 17,032
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	12,312						12,578	(266)
Other comprehensive income	2,102	[1]				2,102
Noncontrolling Interest, cash distributions or proceeds received	152							152
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax of $1,530 (214 shares) and $1,052 (118 shares) for the period March 31, 2014 and 2013, respectively	1,304			163	1,141
Dividends declared ($0.1100 and $0.1067 per common share for the year March 31, 2014 and 2013, respectively)	(2,995)						(2,995)
Performance share unit dividend equivalents	0			55			(55)
Ending Balance at Mar. 31, 2013	624,320		96	181,845	(11,418)	(43,277)	480,156	16,918
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 income	(2,976)	[1]				(2,976)
Noncontrolling Interest, cash distributions or proceeds received	(2,451)							(2,451)
Stock awards, stock option exercises and other shares issued to employees and directors, net of income tax of $1,530 (214 shares) and $1,052 (118 shares) for the period March 31, 2014 and 2013, respectively	1,490			18	1,472
Payment of cash in lieu for stock split (187 shares)	(58)			(58)
Dividends declared ($0.1100 and $0.1067 per common share for the year March 31, 2014 and 2013, 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

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