Unaudited Condensed Consolidated Statement of Equity Statement - USD ($) shares in Thousands, $ 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, 2013	$ 1,424,378	$ 212,327	$ (10)	$ 1,259,348	$ (145,876)	$ 88,441	$ 10,148
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Comprehensive income	75,500	0	0	0	67,024	2,318	$ 6,158
Dividends declared on common stock	(34,024)	0	0	(34,024)	0	0
Employee share-based compensation earned	6,423	0	0	6,423	0	0	$ 0
Stock option exercises	15,552	1,605	0	13,947	0	0	0
Restricted stock awards, net of forfeitures	0	345	0	(345)	0	0	0
Purchase of Company common stock	$ (61,186)	$ 0	$ (3,185)	$ (18,669)	$ (39,332)	$ 0	$ 0
Cancellation of Company Stock	0	(42)	(42)	0	0	0	0
Tax Benefits Related to Share-Based Awards	$ 12,521	$ 0	$ 0	$ 12,521	$ 0	$ 0	$ 0
Purchase of noncontrolling interest	(15,000)	0	0	(7,441)	0	0	(7,559)
Noncontrolling interest payment	(134)	0	0	0	0	0	(134)
Other	1,565	93	0	1,472	0	0	0
Balance at end of period at Jun. 30, 2014	1,425,595	214,328	(3,153)	1,233,232	(118,184)	90,759	8,613
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	13,003	0	0	0
Purchase of noncontrolling interest	0
Noncontrolling interest payment	(60)	$ 0	0	0	0	0	(60)
Other	1,726	62	0	1,664	0	0	0
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