Unaudited Condensed Consolidated Statement of Equity Statement - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Capital in Excess of Par Value	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Balance at beginning of period at Dec. 31, 2014	$ 1,377,378	$ 205,458	$ (591)	$ 1,186,304	$ (81,859)	$ 59,414	$ 8,652
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Comprehensive income	38,832	0	0	0	61,375	(22,617)	74
Dividends declared on common stock	(20,461)	0	0	(20,461)	0	0	0
Employee share-based compensation earned	4,023	0	0	4,023	0	0	0
Stock option exercises	9,445	873	0	8,572	0	0	0
Restricted stock awards, net of forfeitures	0	254	0	(254)	0	0	0
Purchase of Company common stock	(73,180)	0	(3,085)	(17,808)	(52,287)	0	0
Tax Benefits Related to Share-Based Awards	5,511	0	0	5,511	0	0	0
Other	8	1	0	7	0	0	0
Balance at end of period at Mar. 31, 2015	1,341,556	206,586	(3,676)	1,165,894	(72,771)	36,797	8,726
Balance at beginning of period at Dec. 31, 2015	1,189,401	200,859	(5,086)	1,092,106	(109,351)	6,164	4,709
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Comprehensive income	70,170	0	0	0	47,445	22,707	18
Dividends declared on common stock	(23,324)	0	0	(23,324)	0	0	0
Employee share-based compensation earned	3,067	0	0	3,067	0	0	0
Stock option exercises	3,133	417	0	2,716	0	0	0
Restricted stock awards, net of forfeitures	0	242	(1)	(241)	0	0	0
Purchase of Company common stock	(54,632)	0	(2,285)	(12,708)	(39,639)	0	0
Tax Benefits Related to Share-Based Awards	2,258	0	0	2,258	0	0	0
Other	20	2	0	18	0	0	0
Balance at end of period at Mar. 31, 2016	$ 1,190,093	$ 201,520	$ (7,372)	$ 1,063,892	$ (101,545)	$ 28,871	$ 4,727