CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Adjustment for Adoption	Common Stock and Additional Paid-In Capital	Retained Earnings	Retained Earnings Adjustment for Adoption	Cumulative Translation Adjustment	Retirement Benefits Adjustment	Cumulative Unrealized Gain (Loss) on Derivatives	Treasury Stock
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Balance at Dec. 31, 2018	$ 1,994,640	$ 28	$ 739,240	$ 2,342,079	$ 28	$ (94,420)	$ (22,740)	$ (12,065)	$ (957,454)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	110,268			110,268
Cumulative translation adjustment	(3,281)					(3,281)
Net change in retirement obligations (net of tax)	1,262						1,262
Net change on derivatives designated as cash flow hedges (net of tax)	1,227							1,227
Issuance of shares of common stock from issuance of unvested shares, performance share units and exercise of stock options (net of tax)	8,870								8,870
Repurchase of shares of common stock	(51,706)								(51,706)
Shares surrendered for tax withholding	(11,479)								(11,479)
Share-based compensation	5,403		5,403
Balance at Mar. 31, 2019	2,055,232		744,643	2,452,375		(97,701)	(21,478)	(10,838)	(1,011,769)
Balance at Dec. 31, 2018	1,994,640	$ 28	739,240	2,342,079	$ 28	(94,420)	(22,740)	(12,065)	(957,454)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	328,671
Net change in retirement obligations (net of tax)	4,181
Repurchase of shares of common stock	(54,700)
Balance at Sep. 30, 2019	2,163,053		755,601	2,556,423		(132,898)	(18,559)	(8,404)	(989,110)
Balance at Mar. 31, 2019	2,055,232		744,643	2,452,375		(97,701)	(21,478)	(10,838)	(1,011,769)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	113,209			113,209
Cumulative translation adjustment	2,628					2,628
Net change in retirement obligations (net of tax)	1,256						1,256
Net change on derivatives designated as cash flow hedges (net of tax)	1,224							1,224
Issuance of shares of common stock from issuance of unvested shares, performance share units and exercise of stock options (net of tax)	11,891								11,891
Repurchase of shares of common stock	(2,962)								(2,962)
Shares surrendered for tax withholding	(30)								(30)
Share-based compensation	5,266		5,266
Cash dividends declared	(75,673)			(75,673)
Balance at Jun. 30, 2019	2,112,041		749,909	2,489,911		(95,073)	(20,222)	(9,614)	(1,002,870)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	105,194			105,194
Cumulative translation adjustment	(37,825)					(37,825)
Net change in retirement obligations (net of tax)	1,663						1,663
Net change on derivatives designated as cash flow hedges (net of tax)	1,210							1,210
Issuance of shares of common stock from issuance of unvested shares, performance share units and exercise of stock options (net of tax)	14,834								14,834
Shares surrendered for tax withholding	(1,074)								(1,074)
Share-based compensation	5,692		5,692
Cash dividends declared	(38,682)			(38,682)
Balance at Sep. 30, 2019	2,163,053		755,601	2,556,423		(132,898)	(18,559)	(8,404)	(989,110)
Balance at Dec. 31, 2019	2,263,229		761,352	2,615,131		(94,353)	(25,809)	(7,183)	(985,909)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	101,998			101,998
Cumulative translation adjustment	(26,456)					(26,456)
Net change in retirement obligations (net of tax)	2,296						2,296
Net change on derivatives designated as cash flow hedges (net of tax)	1,194							1,194
Issuance of shares of common stock from issuance of unvested shares, performance share units and exercise of stock options (net of tax)	2,089								2,089
Repurchase of shares of common stock	(108,907)								(108,907)
Shares surrendered for tax withholding	(12,119)								(12,119)
Share-based compensation	6,463		6,463
Balance at Mar. 31, 2020	2,229,787		767,815	2,717,129		(120,809)	(23,513)	(5,989)	(1,104,846)
Balance at Dec. 31, 2019	2,263,229		761,352	2,615,131		(94,353)	(25,809)	(7,183)	(985,909)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	276,710
Net change in retirement obligations (net of tax)	1,956
Repurchase of shares of common stock	(110,300)
Balance at Sep. 30, 2020	2,396,529		779,368	2,778,130		(54,195)	(23,853)	(3,201)	(1,079,720)
Balance at Mar. 31, 2020	2,229,787		767,815	2,717,129		(120,809)	(23,513)	(5,989)	(1,104,846)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	70,864			70,864
Cumulative translation adjustment	19,271					19,271
Net change in retirement obligations (net of tax)	(631)						(631)
Net change on derivatives designated as cash flow hedges (net of tax)	2,116							2,116
Issuance of shares of common stock from issuance of unvested shares, performance share units and exercise of stock options (net of tax)	11,022								11,022
Repurchase of shares of common stock	(1,435)								(1,435)
Shares surrendered for tax withholding	(29)								(29)
Share-based compensation	5,753		5,753
Cash dividends declared	(75,681)			(75,681)
Balance at Jun. 30, 2020	2,261,037		773,568	2,712,312		(101,538)	(24,144)	(3,873)	(1,095,288)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	103,848			103,848
Cumulative translation adjustment	47,343					47,343
Net change in retirement obligations (net of tax)	291						291
Net change on derivatives designated as cash flow hedges (net of tax)	672							672
Issuance of shares of common stock from issuance of unvested shares, performance share units and exercise of stock options (net of tax)	15,618								15,618
Shares surrendered for tax withholding	(50)								(50)
Share-based compensation	5,800		5,800
Cash dividends declared	(38,030)			(38,030)
Balance at Sep. 30, 2020	$ 2,396,529		$ 779,368	$ 2,778,130		$ (54,195)	$ (23,853)	$ (3,201)	$ (1,079,720)