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	99,798	0	0	0	113,970	(14,746)	574
Dividends declared on common stock	(40,398)	0	0	(40,398)	0	0	0
Employee share-based compensation earned	7,284	0	0	7,284	0	0	0
Stock option exercises	26,799	2,432	0	24,367	0	0	0
Restricted stock awards, net of forfeitures	0	254	0	(254)	0	0	0
Purchase of Company common stock	(151,795)	0	(5,864)	(33,849)	(112,082)	0	0
Tax Benefits Related to Share-Based Awards	13,003	0	0	13,003	0	0	0
Other	1,666	62	0	1,664	0	0	(60)
Balance at end of period at Jun. 30, 2015	1,333,735	208,206	(6,455)	1,158,121	(79,971)	44,668	9,166
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	86,481	0	0	0	63,065	23,125	291
Dividends declared on common stock	(48,506)	0	0	(48,506)	0	0	0
Employee share-based compensation earned	6,574	0	0	6,574	0	0	0
Stock option exercises	8,872	871	0	8,001	0	0	0
Restricted stock awards, net of forfeitures	0	242	(1)	(241)	0	0	0
Purchase of Company common stock	(81,477)	0	(3,311)	(18,333)	(59,833)	0	0
Tax Benefits Related to Share-Based Awards	4,269	0	0	4,269	0	0	0
Other	2,206	95	0	2,191	0	0	(80)
Balance at end of period at Jun. 30, 2016	$ 1,167,820	$ 202,067	$ (8,398)	$ 1,046,061	$ (106,119)	$ 29,289	$ 4,920