Shareholders' Equity Textuals (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Cross Currency Swap interest portion recognized in income	$ 800
Common Stock, Shares Authorized	125,000,000	125,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Voting Rights	one
Common Stock Reserved for Issuance to the Stock Option Plans	3,252,712
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Par Value	$ 0.01	$ 0.01
Share Repurchase Program and Treasury Stock [Abstract]
Treasury Stock Acquired, Repurchase Authorization	2.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 2,100,000
Shares Repurchased Under Share Repurchase Program	27,500,000
Share Repurchase Program, Total Cost Program to Date	$ 4,400,000
Repurchases of Common Stock, Value	$ (474,999)	$ (399,997)	$ (499,992)
Repurchases of Common Stock, Shares	(802,809)	(749,254)
Treasury Stock Acquired, Average Cost Per Share	$ 591.65	$ 533.84
Exercise of stock options and restricted stock units, shares	183,379	270,413
Cross Currency Swap Revaluation Portion Recognized in Earnings	$ 3,000