Calculation Of Net Income Per Share (Weighted-Average Shares Used In Calculation Of Basic And Diluted EPS) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Weighted-average number of common shares outstanding	107,001	114,155	126,710
Conversion spread related to Convertible Debentures	21,074	18,047	13,384
Unvested restricted stock units	758	829	801
Shares used to compute diluted net income per share	128,833	133,031	140,895