Earnings Per Share (Computation Of Net Income Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Basic earnings per share:
Net income	$ 53,115	$ 2,689
Weighted-average common shares outstanding	59,817	55,972
Basic earnings per share (in dollars per share)	$ 0.89	$ 0.05
Diluted earnings per share:
Net income	53,115	2,689
Senior Convertible Notes interest expense, net of tax	0	49
Numerator for diluted earnings per share	$ 53,115	$ 2,738
Shares used in computation:
Weighted-average common shares outstanding	59,817	55,972
Senior Convertible Notes shares	0	2,331
Employee stock options	1,731	1,843
Weighted-average number of shares - Diluted	61,548	60,146
Diluted earnings per share (in dollars per share)	$ 0.86	$ 0.05