Consolidated Statement of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Treasury Stock	Capital in Excess of Par Value	Accumulated Deficit(1)	Accumulated Other Comprehensive Income	Noncontrolling Interest
Balance at beginning of period at Dec. 31, 2016	$ 1,095,247	$ 195,403	$ (5,998)	$ 990,203	$ (103,387)	$ 16,492	$ 2,534
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Comprehensive income	572,309	0	0	0	546,663	25,451	195
Dividends declared on common stock	(108,750)	0	0	(37,011)	(71,739)	0	0
Stock option exercises	33,611	2,759	0	30,852	0	0	0
Restricted stock awards, net of forfeitures	0	209	(2)	(207)	0	0	0
Employee share-based compensation earned	14,788		0
Purchase of Company common stock	(199,637)	0		14,788	0	0	0
Purchase of noncontrolling interest	(4,580)	0	(6,211)	(32,253)	(161,173)	0	0
Acquisition		0	0	(2,258)	0	0	(2,322)
Noncontrolling interest payments	$ (360)	$ 0	$ 0	$ 0	$ 0	$ 0	$ (360)
Retirement of treasury shares	0	(6,890)	(6,890)	0	0	0	0
Other	$ 6,809	$ 455	$ 0	$ 6,354	$ 0	$ 0	$ 0
Balance at end of period at Dec. 31, 2017	1,409,437	191,936	(5,321)	970,468	210,364	41,943	47
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Comprehensive income	419,080	0	0	0	447,208	(28,319)	191
Dividends declared on common stock	(123,849)	0	0	0	(123,849)	0	0
Stock option exercises	24,517	1,802	0	22,715	0	0	0
Restricted stock awards, net of forfeitures	0	178	0	(178)	0	0	0
Employee share-based compensation earned	15,626	0	0	15,626	0	0	0
Purchase of Company common stock	(277,611)	0	(7,348)	(38,404)	(231,859)	0	0
Noncontrolling interest payments	$ (326)	$ 0	$ 0	$ 0	$ 0	$ 0	$ (326)
Retirement of treasury shares	0	(9,419)	(9,419)	0	0	0	0
Other	$ 2,709	$ 224	$ 0	$ 2,483	$ 2	$ 0	$ 0
Balance at end of period at Dec. 31, 2018	1,641,815	184,721	(3,250)	972,710	474,327	13,395	(88)
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	172,232	0	0	0	172,461	(229)	0
Comprehensive income	386,241	0	0	0	369,596	16,469	176
Dividends declared on common stock	(131,402)	0	0	0	(131,402)	0	0
Stock option exercises	40,922	2,394	0	38,528	0	0	0
Restricted stock awards, net of forfeitures	0	126	0	(126)	0	0	0
Employee share-based compensation earned	15,029	0	0	15,029	0	0	0
Purchase of Company common stock	(129,589)	0	(2,909)	(16,062)	(110,618)	0	0
Noncontrolling interest payments	$ (146)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 146
Retirement of treasury shares	0	(2,243)	(2,243)	0	0	0	0
Other	$ 385	$ 103	$ 0	$ 282	$ 0	$ 0	$ 0
Balance at end of period at Dec. 31, 2019	$ 1,823,255	$ 185,101	$ (3,916)	$ 1,010,361	$ 601,903	$ 29,864	$ (58)