Calculation Of Net Income Per Share (Weighted-Average Shares Used In Calculation Of Basic And Diluted EPS) (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Weighted-average number of common shares outstanding	115,656	129,350	116,394	131,372
Conversion spread related to Convertible Debentures	16,973	11,291	16,392	12,788
Unvested restricted stock units	580	462	725	640
Employee stock purchase plan	42	39	35	61
Shares used to compute diluted net income per share	133,251	141,142	133,546	144,861