CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - 9 months ended Sep. 30, 2017 - USD ($) $ in Thousands	Total	Common Stock and Additional Paid-In Capital	Retained Earnings	Cumulative Translation Adjustment	Retirement Benefits Adjustment	Cumulative Unrealized Gain (Loss) on Derivatives	Treasury Stock
Balance, December 31, 2016 at Dec. 31, 2016	$ 1,543,894	$ 698,115	$ 1,834,739	$ (155,544)	$ (27,852)	$ (18,257)	$ (787,307)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	243,511		243,511
Cumulative translation adjustment	97,160			97,160
Net change in retirement obligations (net of tax of $1,753)	3,872				3,872
Net change on derivatives designated as cash flow hedges (net of tax of $1,845)	3,159					3,159
Issuance of 470,104 shares of common stock from issuance of unvested shares, performance share units and exercise of stock options (net of tax of $5,579)	18,980						18,980
Repurchase of 222,000 shares of common stock	(23,627)						(23,627)
Unvested shares surrendered for tax withholding	(5,903)						(5,903)
Share-based compensation	14,878	14,878
Cash dividends declared - $1.11 per common share outstanding	(85,612)		(85,612)
Balance, September 30, 2017 at Sep. 30, 2017	$ 1,810,312	$ 712,993	$ 1,992,638	$ (58,384)	$ (23,980)	$ (15,098)	$ (797,857)