Summary Of Significant Accounting Policies (Calculation Of Basic And Diluted Earnings Per Common Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary Of Significant Accounting Policies [Abstract]
Net income	$ 24,817	$ 35,357	$ 36,894	$ 36,585	$ 38,158	$ 32,639	$ 33,010	$ 27,363	$ 133,653	$ 131,170	$ 116,061
Less: dividends on preferred stock and accretion											19,524
Net income available to common stockholders									$ 133,653	$ 131,170	$ 96,537
Basic weighted-average number of common shares outstanding	170,185,439	170,007,399	169,843,354	169,671,128	169,426,058	169,177,275	169,009,302	168,831,733	169,928,460	169,112,901	159,259,476
Plus: Common stock equivalents									1,130	8,683	753
Diluted weighted-average number of common shares outstanding	170,185,880	170,007,983	169,852,912	169,678,846	169,428,992	169,178,469	169,013,634	168,834,400	169,929,590	169,121,584	159,260,229
Basic	$ 0.15	$ 0.21	$ 0.22	$ 0.22	$ 0.23	$ 0.19	$ 0.20	$ 0.16	$ 0.79	$ 0.78	$ 0.61
Diluted	$ 0.15	$ 0.21	$ 0.22	$ 0.22	$ 0.23	$ 0.19	$ 0.20	$ 0.16	$ 0.79	$ 0.78	$ 0.61