Business Combinations (Summary Of FDIC Indemnification Asset) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Business Combinations [Abstract]
Balance at the beginning of period	$ 344,251	$ 118,182
Additions	20,028	51,159
Accretion	(1,576)	359
Changes in expected reimbursements from the FDIC for changes in expected credit losses	(17,213)	(9,406)
Payments received from the FDIC	(82,278)	(35,509)
Balance at the end of period	$ 263,212	$ 124,785