Earnings Per Share (Computations Of Basic And Diluted EPS) (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Basic:
Net income applicable to common shareholders	$ 9,880	$ 75,586	$ 26,887	$ 187,087
Less undistributed income allocated to participating securities	(52)	(392)	(149)	(980)
Undistributed income allocated to common shares	$ 9,828	$ 75,194	$ 26,738	$ 186,107
Weighted average number of shares outstanding (in shares)	105,438	104,997	105,362	105,038
Diluted:
Undistributed income allocated to common shares	$ 9,828	$ 75,194	$ 26,738	$ 186,107
Share-based awards other than participating securities	$ 0	$ 0	$ 0	$ 0
Share-based awards other than participating securities (in shares)	0	341	0	336
Undistributed income reallocated to participating securities	$ 0	$ 1	$ 0	$ 3
Net income applicable to common shareholders	$ 9,828	$ 75,195	$ 26,738	$ 186,110
Weighted average number of shares outstanding (in shares)	105,438	105,338	105,362	105,374