Loans (Details 3) (USD $)				6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Jun. 30, 2012 Greater than	Jun. 30, 2012 Commercial	Dec. 31, 2011 Commercial	Jun. 30, 2011 Commercial	Jun. 30, 2012 Real estate - commercial	Jun. 30, 2011 Real estate - commercial	Jun. 30, 2012 Real estate - commercial Owner occupied general purpose	Dec. 31, 2011 Real estate - commercial Owner occupied general purpose	Jun. 30, 2012 Real estate - commercial Owner occupied special purpose	Dec. 31, 2011 Real estate - commercial Owner occupied special purpose	Jun. 30, 2012 Real estate - commercial Non-owner occupied general purpose	Dec. 31, 2011 Real estate - commercial Non-owner occupied general purpose	Jun. 30, 2012 Real estate - commercial Non-owner occupied special purpose	Dec. 31, 2011 Real estate - commercial Non-owner occupied special purpose	Jun. 30, 2012 Real estate - commercial Retail properties	Dec. 31, 2011 Real estate - commercial Retail properties	Jun. 30, 2012 Real estate - commercial Farm	Dec. 31, 2011 Real estate - commercial Farm	Jun. 30, 2012 Real estate - construction	Jun. 30, 2011 Real estate - construction	Jun. 30, 2012 Real estate - construction Homebuilder	Dec. 31, 2011 Real estate - construction Homebuilder	Jun. 30, 2012 Real estate - construction Land	Dec. 31, 2011 Real estate - construction Land	Jun. 30, 2012 Real estate - construction Commercial speculative	Dec. 31, 2011 Real estate - construction Commercial speculative	Jun. 30, 2012 Real estate - construction All other	Dec. 31, 2011 Real estate - construction All other	Jun. 30, 2012 Real estate - residential	Jun. 30, 2011 Real estate - residential	Jun. 30, 2012 Real estate - residential Investor	Dec. 31, 2011 Real estate - residential Investor	Jun. 30, 2012 Real estate - residential Owner occupied	Dec. 31, 2011 Real estate - residential Owner occupied	Jun. 30, 2012 Real estate - residential Revolving and junior liens	Dec. 31, 2011 Real estate - residential Revolving and junior liens	Jun. 30, 2012 Consumer	Dec. 31, 2011 Consumer	Jun. 30, 2011 Consumer	Jun. 30, 2012 All other	Dec. 31, 2011 All other	Jun. 30, 2011 All other	Jun. 30, 2012 Pass	Dec. 31, 2011 Pass	Jun. 30, 2012 Pass Commercial	Dec. 31, 2011 Pass Commercial	Jun. 30, 2012 Pass Real estate - commercial Owner occupied general purpose	Dec. 31, 2011 Pass Real estate - commercial Owner occupied general purpose	Jun. 30, 2012 Pass Real estate - commercial Owner occupied special purpose	Dec. 31, 2011 Pass Real estate - commercial Owner occupied special purpose	Jun. 30, 2012 Pass Real estate - commercial Non-owner occupied general purpose	Dec. 31, 2011 Pass Real estate - commercial Non-owner occupied general purpose	Jun. 30, 2012 Pass Real estate - commercial Non-owner occupied special purpose	Dec. 31, 2011 Pass Real estate - commercial Non-owner occupied special purpose	Jun. 30, 2012 Pass Real estate - commercial Retail properties	Dec. 31, 2011 Pass Real estate - commercial Retail properties	Jun. 30, 2012 Pass Real estate - commercial Farm	Dec. 31, 2011 Pass Real estate - commercial Farm	Jun. 30, 2012 Pass Real estate - construction Homebuilder	Dec. 31, 2011 Pass Real estate - construction Homebuilder	Jun. 30, 2012 Pass Real estate - construction Land	Dec. 31, 2011 Pass Real estate - construction Land	Jun. 30, 2012 Pass Real estate - construction Commercial speculative	Dec. 31, 2011 Pass Real estate - construction Commercial speculative	Jun. 30, 2012 Pass Real estate - construction All other	Dec. 31, 2011 Pass Real estate - construction All other	Jun. 30, 2012 Pass Real estate - residential Investor	Dec. 31, 2011 Pass Real estate - residential Investor	Jun. 30, 2012 Pass Real estate - residential Owner occupied	Dec. 31, 2011 Pass Real estate - residential Owner occupied	Jun. 30, 2012 Pass Real estate - residential Revolving and junior liens	Dec. 31, 2011 Pass Real estate - residential Revolving and junior liens	Jun. 30, 2012 Pass Consumer	Dec. 31, 2011 Pass Consumer	Jun. 30, 2012 Pass All other	Dec. 31, 2011 Pass All other	Jun. 30, 2012 Special Mention	Dec. 31, 2011 Special Mention	Jun. 30, 2012 Special Mention Commercial	Dec. 31, 2011 Special Mention Commercial	Jun. 30, 2012 Special Mention Real estate - commercial Owner occupied general purpose	Dec. 31, 2011 Special Mention Real estate - commercial Owner occupied general purpose	Jun. 30, 2012 Special Mention Real estate - commercial Owner occupied special purpose	Dec. 31, 2011 Special Mention Real estate - commercial Owner occupied special purpose	Jun. 30, 2012 Special Mention Real estate - commercial Non-owner occupied general purpose	Dec. 31, 2011 Special Mention Real estate - commercial Non-owner occupied general purpose	Jun. 30, 2012 Special Mention Real estate - commercial Non-owner occupied special purpose	Dec. 31, 2011 Special Mention Real estate - commercial Non-owner occupied special purpose	Jun. 30, 2012 Special Mention Real estate - commercial Retail properties	Dec. 31, 2011 Special Mention Real estate - commercial Retail properties	Jun. 30, 2012 Special Mention Real estate - commercial Farm	Dec. 31, 2011 Special Mention Real estate - commercial Farm	Jun. 30, 2012 Special Mention Real estate - construction Homebuilder	Dec. 31, 2011 Special Mention Real estate - construction Homebuilder	Dec. 31, 2011 Special Mention Real estate - construction Land	Jun. 30, 2012 Special Mention Real estate - construction All other	Dec. 31, 2011 Special Mention Real estate - construction All other	Jun. 30, 2012 Special Mention Real estate - residential Investor	Dec. 31, 2011 Special Mention Real estate - residential Investor	Jun. 30, 2012 Special Mention Real estate - residential Owner occupied	Dec. 31, 2011 Special Mention Real estate - residential Owner occupied	Jun. 30, 2012 Special Mention Real estate - residential Revolving and junior liens	Dec. 31, 2011 Special Mention Real estate - residential Revolving and junior liens	Jun. 30, 2012 Special Mention All other	Dec. 31, 2011 Special Mention All other	Jun. 30, 2012 Substandard	Dec. 31, 2011 Substandard	Jun. 30, 2012 Substandard Commercial	Dec. 31, 2011 Substandard Commercial	Jun. 30, 2012 Substandard Real estate - commercial	Jun. 30, 2011 Substandard Real estate - commercial	Jun. 30, 2012 Substandard Real estate - commercial Owner occupied general purpose	Dec. 31, 2011 Substandard Real estate - commercial Owner occupied general purpose	Jun. 30, 2012 Substandard Real estate - commercial Owner occupied special purpose	Dec. 31, 2011 Substandard Real estate - commercial Owner occupied special purpose	Jun. 30, 2012 Substandard Real estate - commercial Non-owner occupied general purpose	Dec. 31, 2011 Substandard Real estate - commercial Non-owner occupied general purpose	Jun. 30, 2012 Substandard Real estate - commercial Non-owner occupied special purpose	Dec. 31, 2011 Substandard Real estate - commercial Non-owner occupied special purpose	Jun. 30, 2012 Substandard Real estate - commercial Retail properties	Dec. 31, 2011 Substandard Real estate - commercial Retail properties	Jun. 30, 2012 Substandard Real estate - commercial Farm	Dec. 31, 2011 Substandard Real estate - commercial Farm	Jun. 30, 2012 Substandard Real estate - construction Homebuilder	Dec. 31, 2011 Substandard Real estate - construction Homebuilder	Jun. 30, 2012 Substandard Real estate - construction Land	Dec. 31, 2011 Substandard Real estate - construction Land	Jun. 30, 2012 Substandard Real estate - construction Commercial speculative	Dec. 31, 2011 Substandard Real estate - construction Commercial speculative	Jun. 30, 2012 Substandard Real estate - construction All other	Dec. 31, 2011 Substandard Real estate - construction All other	Jun. 30, 2012 Substandard Real estate - residential Investor	Dec. 31, 2011 Substandard Real estate - residential Investor	Jun. 30, 2012 Substandard Real estate - residential Owner occupied	Dec. 31, 2011 Substandard Real estate - residential Owner occupied	Jun. 30, 2012 Substandard Real estate - residential Revolving and junior liens	Dec. 31, 2011 Substandard Real estate - residential Revolving and junior liens	Jun. 30, 2012 Substandard Consumer	Dec. 31, 2011 Substandard Consumer
Loans by risk rating
Loan commitment for inclusion in credit quality analysis				$ 50,000
Total	$ 1,238,134,000	$ 1,368,985,000	$ 1,530,406,000		$ 92,695,000	$ 100,186,000	$ 123,205,000	$ 625,056,000	$ 765,599,000	$ 133,261,000	$ 150,906,000	$ 169,333,000	$ 189,227,000	$ 146,291,000	$ 160,781,000	$ 94,135,000	$ 109,239,000	$ 53,646,000	$ 58,432,000	$ 28,390,000	$ 35,907,000	$ 57,064,000	$ 94,529,000	$ 13,773,000	$ 18,918,000	$ 8,918,000	$ 10,001,000	$ 15,229,000	$ 20,040,000	$ 19,144,000	$ 22,477,000	$ 447,151,000	$ 519,907,000	$ 169,127,000	$ 181,112,000	$ 128,508,000	$ 138,312,000	$ 149,516,000	$ 157,776,000	$ 3,321,000	$ 3,789,000	$ 4,361,000	$ 12,847,000	$ 11,882,000	$ 22,805,000	$ 1,013,729,000	$ 1,036,736,000	$ 86,830,000	$ 94,456,000	$ 116,221,000	$ 115,175,000	$ 139,707,000	$ 154,650,000	$ 95,441,000	$ 102,178,000	$ 86,120,000	$ 85,931,000	$ 31,643,000	$ 26,391,000	$ 22,964,000	$ 26,629,000	$ 3,764,000	$ 4,206,000	$ 5,772,000	$ 3,755,000	$ 2,587,000	$ 1,306,000	$ 16,130,000	$ 17,448,000	$ 131,224,000	$ 119,494,000	$ 114,603,000	$ 118,658,000	$ 144,782,000	$ 151,928,000	$ 3,314,000	$ 3,776,000	$ 12,627,000	$ 10,755,000	$ 75,457,000	$ 99,810,000	$ 4,456,000	$ 3,350,000	$ 4,893,000	$ 11,695,000	$ 5,880,000	$ 5,254,000	$ 20,607,000	$ 19,292,000	$ 6,495,000	$ 6,017,000	$ 4,524,000	$ 11,660,000	$ 3,148,000	$ 5,605,000	$ 2,741,000	$ 2,905,000	$ 3,032,000	$ 2,885,000	$ 303,000	$ 18,705,000	$ 28,478,000	$ 493,000	$ 271,000	$ 410,000	$ 821,000	$ 220,000	$ 1,127,000	$ 148,948,000	$ 232,439,000	$ 1,409,000	$ 2,380,000	$ 28,200,000	$ 100,900,000	$ 12,147,000	$ 24,036,000	$ 23,746,000	$ 29,323,000	$ 30,243,000	$ 39,311,000	$ 1,520,000	$ 17,291,000	$ 17,479,000	$ 20,381,000	$ 2,278,000	$ 3,673,000	$ 7,268,000	$ 11,807,000	$ 3,146,000	$ 3,214,000	$ 12,642,000	$ 18,734,000	$ 129,000	$ 4,726,000	$ 19,198,000	$ 33,140,000	$ 13,412,000	$ 19,383,000	$ 4,324,000	$ 5,027,000	$ 7,000	$ 13,000