Calculation Of Net Income Per Share (Weighted-Average Shares Used In Calculation Of Basic And Diluted EPS) (Details) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Weighted-average number of common shares outstanding	133,417	152,543
Conversion spread related to Convertible Debentures	14,286	7,904
Unvested restricted stock units	817	787
Stock options	37	104
Employee stock purchase plan	43	8
Shares used to compute diluted net income per share	148,600	161,346