CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock and Additional Paid-In Capital	Retained Earnings	Cumulative Translation Adjustment	Retirement Benefits Adjustments	Cumulative Unrealized Gain (Loss) on Derivatives	Treasury Stock
Balance at Dec. 31, 2013	$ 1,572,989	$ 608,658	$ 1,293,740	$ 52,211	$ (23,857)	$ (31,659)	$ (326,104)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	279,386		279,386
Cumulative translation adjustment	(77,024)			(77,024)
Net change in retirement obligations, net of tax	(16,459)				(16,459)
Net change on derivatives designated as cash flow hedges, net of tax	4,510					4,510
Issuance of common stock from issuance of unvested shares, exercise of stock options and deferred compensation plans, net of tax	23,195	23,195
Repurchase of common stock	(222,487)						(222,487)
Share-based compensation	16,598	16,598
Unvested shares surrendered for tax withholding	(4,952)						(4,952)
Cash dividends declared	(89,305)		(89,305)
Balance at Dec. 31, 2014	1,486,451	648,451	1,483,821	(24,813)	(40,316)	(27,149)	(553,543)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	282,807		282,807
Cumulative translation adjustment	(68,166)			(68,166)
Net change in retirement obligations, net of tax	9,415				9,415
Net change on derivatives designated as cash flow hedges, net of tax	4,531					4,531
Issuance of common stock from issuance of unvested shares, exercise of stock options and deferred compensation plans, net of tax	24,482	14,545					9,937
Repurchase of common stock	(210,551)						(210,551)
Share-based compensation	17,529	17,529
Unvested shares surrendered for tax withholding	(3,259)						(3,259)
Cash dividends declared	(99,948)		(99,948)
Balance at Dec. 31, 2015	1,443,291	680,525	1,666,680	(92,979)	(30,901)	(22,618)	(757,416)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	271,109		271,109
Cumulative translation adjustment	(62,565)			(62,565)
Net change in retirement obligations, net of tax	3,049				3,049
Net change on derivatives designated as cash flow hedges, net of tax	4,361					4,361
Issuance of common stock from issuance of unvested shares, exercise of stock options and deferred compensation plans, net of tax	30,240	253					29,987
Repurchase of common stock	(54,950)						(54,950)
Share-based compensation	17,337	17,337
Unvested shares surrendered for tax withholding	(4,928)						(4,928)
Cash dividends declared	(103,050)		(103,050)
Balance at Dec. 31, 2016	$ 1,543,894	$ 698,115	$ 1,834,739	$ (155,544)	$ (27,852)	$ (18,257)	$ (787,307)