Summary Of Significant Accounting Policies Summary Of Significant Accounting Policies (Earnings per share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Numerator:
Net income	$ 103,324	$ 41,880	$ 158,295	$ 116,699
Less: earnings distributed to participating securities	(185)	(130)	(373)	(263)
Less: undistributed earnings allocated to participating securities	(475)	(159)	(647)	(546)
Numerator for basic earnings per share	102,664	41,591	157,275	115,890
Add back: undistributed earnings allocated to participating securities	475	159	647	546
Less: undistributed earnings reallocated to participating securities	(471)	(157)	(641)	(540)
Numerator for diluted earnings per share	$ 102,668	$ 41,593	$ 157,281	$ 115,896
Denominator:
Basic shares outstanding (shares)	361,009	376,072	363,863	377,410
Effect of dilutive securities (shares)	3,232	3,592	3,297	3,703
Diluted shares outstanding (shares)	364,241	379,664	367,160	381,113
Earnings Per Share [Abstract]
Earnings Per Share, Basic (usd per share)	$ 0.28	$ 0.11	$ 0.43	$ 0.31
Earnings Per Share, Diluted (usd per share)	$ 0.28	$ 0.11	$ 0.43	$ 0.30