Fair Value Measurement (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Assets measured at fair value on a nonrecurring basis
Mortgage Servicing rights	$ 17,749	$ 21,579
Nonrecurring [Member]
Assets measured at fair value on a nonrecurring basis
Mortgage Servicing rights	17,749	0
Impaired and nonaccrual loans	75,992	140,990
Other property	18,933	22,974
Other real estate covered by loss share	62,737	59,132
Total assets at fair value on a recurring and nonrecurring basis	175,411	223,096
Level 1 [Member] | Nonrecurring [Member]
Assets measured at fair value on a nonrecurring basis
Mortgage Servicing rights	0	0
Impaired and nonaccrual loans	0	0
Other property	0	0
Other real estate covered by loss share	0	0
Total assets at fair value on a recurring and nonrecurring basis	0	0
Level 2 [Member] | Nonrecurring [Member]
Assets measured at fair value on a nonrecurring basis
Mortgage Servicing rights	0	0
Impaired and nonaccrual loans	0	0
Other property	0	0
Other real estate covered by loss share	0	0
Total assets at fair value on a recurring and nonrecurring basis	0	0
Level 3 [Member] | Nonrecurring [Member]
Assets measured at fair value on a nonrecurring basis
Mortgage Servicing rights	17,749	0
Impaired and nonaccrual loans	75,992	140,990
Other property	18,933	22,974
Other real estate covered by loss share	62,737	59,132
Total assets at fair value on a recurring and nonrecurring basis	$ 175,411	$ 223,096