Net Earnings Per Common Share (Basic And Diluted Net Earnings Per Common Share Based On The Weighted Average Outstanding Shares) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 137,401	$ 127,263	$ 113,949	$ 90,437	$ 102,487	$ 100,999	$ 13,960	$ 92,025	$ 469,050	$ 309,471	$ 398,462
Less common and preferred dividends, Basic									(115,418)	(107,990)	(103,111)
Undistributed Earnings, Diluted									353,632	201,481	295,351
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic									3,802	1,836	2,933
Undistributed earnings (loss) applicable to nonvested shares, Basic									349,830	199,645	292,418
Distributed earnings applicable to common shares, Basic									(57,180)	(44,816)	(30,983)
Net earnings (loss) applicable to common shareholders									$ 407,010	$ 244,461	$ 323,401
Weighted average common shares outstanding									203,855	203,265	192,207
Net earnings (loss) per common share, Basic	$ 0.61	$ 0.57	$ 0.44	$ 0.38	$ 0.43	$ 0.41	$ (0.01)	$ 0.37	$ 2.00	$ 1.20	$ 1.68
Additional weighted average dilutive shares, Diluted									414	433	582
Weighted average diluted common shares outstanding, Diluted									204,269	203,698	192,789
Net earnings (loss) per common share, Diluted	$ 0.60	$ 0.57	$ 0.44	$ 0.38	$ 0.43	$ 0.41	$ (0.01)	$ 0.37	$ 1.99	$ 1.20	$ 1.68