Estimated Fair Values Estimated Fair Values (Information on Other Real Estate Owned) (Details) (Fair Value, Measurements, Nonrecurring, Fair Value, Inputs, Level 3, USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Covered OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current year foreclosures	$ 41,098	$ 68,375	$ 61,630	$ 109,175
Loan charge-offs recorded due to the measurement and initial recognition of OREO	7,392	7,447	8,351	7,447
Write-downs recorded subsequent to forelosure for OREO	11,137	11,431	11,259	15,997
Fair value of OREO remeasured in current year	24,136	7,759	33,697	12,572
Non-covered OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current year foreclosures	12,475	19,765	18,783	13,636
Loan charge-offs recorded due to the measurement and initial recognition of OREO	130	1,385	588	2,053
Write-downs recorded subsequent to forelosure for OREO	2,629	2,433	3,112	1,684
Fair value of OREO remeasured in current year	$ 9,301	$ 17,272	$ 12,893	$ 6,567