Fair Value (Narrative) (Details) (USD $)	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Jun. 30, 2011	Dec. 31, 2010	Mar. 31, 2011
Fair Value
Book value of impaired loans	$ 200,400,000	$ 200,400,000	$ 250,933,000
Partial charge-offs on impaired loans		88,700,000	53,600,000
Valuation allowance of impaired loans	32,810,000	32,810,000	43,459,000
Book value of impaired loans carried at fair value	130,400,000	130,400,000
Remaining amount of impaired loans carried at cost		70,000,000	96,200,000
MSR recorded at lower of cost or fair value	10,259,000	10,259,000	10,488,000	10,365,000
Mortgage servicing rights	2,526,000	2,526,000	3,813,000
Valuation allowance of MSR	680,000	680,000	748,000	680,000
MSRs recorded at cost	7,800,000	7,800,000
Devaluation adjustments of OREO	5,300,000	9,700,000
Impaired loans carried at fair value, Fair value	97,608,000	97,608,000	111,257,000
Estimated fair value of OREO, less estimated selling costs	$ 47,997,000	$ 47,997,000	$ 44,325,000