Earnings Per Share (Computations Of Basic And Diluted EPS) (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Basic:
Net income applicable to common shareholders	$ (2,635)	$ 57,782	$ 17,007	$ 111,501
Less undistributed income allocated to participating securities	0	(300)	(96)	(586)
Undistributed income allocated to common shares	$ (2,635)	$ 57,482	$ 16,911	$ 110,915
Weighted average number of shares outstanding (in shares)	105,357	104,992	105,324	105,059
Diluted:
Undistributed income allocated to common shares	$ (2,635)	$ 57,482	$ 16,911	$ 110,915
Share-based awards other than participating securities			$ 0	$ 0
Share-based awards other than participating securities (in shares)	0	303	0	300
Undistributed income reallocated to participating securities	$ 0	$ 1	$ 0	$ 2
Net income applicable to common shareholders	$ (2,635)	$ 57,483	$ 16,911	$ 110,917
Weighted average number of shares outstanding (in shares)	105,357	105,295	105,324	105,359