Summary of Significant Accounting Policies (Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accounting Policies [Abstract]
Basic earnings per common share, Income (Numerator)	$ 83,983	$ 67,195	$ 241,616	$ 222,609
Shares used to compute basic earnings per share	167,925	171,308	168,612	172,043
Basic earnings per common share	$ 0.50	$ 0.39	$ 1.43	$ 1.29
Dilutive effect of stock options, income	0	0	0	0
Dilutive effect of stock options, shares	4,980	4,735	5,088	3,993
Diluted earnings per common share, Income (Numerator)	$ 83,983	$ 67,195	$ 241,616	$ 222,609
Shares used to compute diluted earnings per share	172,905	176,043	173,700	176,036
Diluted earnings per common share	$ 0.49	$ 0.38	$ 1.39	$ 1.26

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Amount of increase (decrease) to net income used for calculating diluted earnings per share (EPS), resulting from the assumed exercise of stock options or restrictive stock units (RSUs).

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Net Income or Loss Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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