Unaudited Condensed Consolidated Statement of Equity Statement (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Treasury Stock [Member]	Capital in Excess of Par Value [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
Balance at beginning of period at Dec. 31, 2010	$ 1,479,948	$ 242,020	$ (985)	$ 1,603,112	$ (477,459)	$ 112,768	$ 492
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Comprehensive income	76,587	0	0	0	64,857	9,916	1,814
Net Income (Loss) Attributable to Parent	64,857
Dividends declared on common stock	(23,788)	0	0	(23,788)	0	0	0
Employee share-based compensation earned	4,542	0	0	4,542	0	0	0
Stock option exercises	6,862	1,016	0	5,846	0	0	0
Restricted stock awards, net of forfeitures	0	539	0	(539)	0	0	0
Purchase of Company common stock	(55,644)	0	(5,455)	(50,189)	0	0	0
Acquisition	18,857	0	0	0	0	0	18,857
Noncontrolling interest payment	(568)	0	0	0	0	0	(568)
Other	753	72	1	680	0	0	0
Balance at end of period at Jun. 30, 2011
Balance at beginning of period at Dec. 31, 2011	1,412,195	224,666	(1,710)	1,430,330	(367,044)	105,852	20,101
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Comprehensive income	83,432	0	0	0		(2,524)	855
Net Income (Loss) Attributable to Parent	85,101
Dividends declared on common stock	(23,802)	0	0	(23,802)	0	0	0
Employee share-based compensation earned	4,969	0	0	4,969	0	0	0
Stock option exercises	3,793	635	0	3,158	0	0	0
Restricted stock awards, net of forfeitures	0	483	0	(483)	0	0	0
Purchase of Company common stock	(104,700)	0	(9,385)	(60,802)	(34,513)	0	0
Noncontrolling interest payment	(405)	0	0	0	0	0	(405)
Other	948	82		866	0	0	0
Balance at end of period at Jun. 30, 2012	$ 1,376,430	$ 225,866	$ (11,095)	$ 1,354,236	$ (316,456)	$ 103,328	$ 20,551