Business Combinations (Details 3) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	May 28, 2010 Granite [Member]
Asset acquired:
Cash and cash equivalents				$ 18,764,000
Securities available-for-sale	163,027,000	229,223,000		2,954,000
Restricted equity securities	9,647,000	10,610,000		696,000
Covered loans				64,802,000
Premises and equipment				17,000
Core deposit intangible				562,000
Covered foreclosed assets				4,629,000
FDIC Indemnification Asset	1,997,000	4,405,000	5,640,000	7,466,000
Other assets				392,000
Total assets acquired				100,282,000
Liabilities assumed:
Deposits	2,289,702,000	2,190,536,000		95,001,000
Other borrowings	9,197,000	72,541,000		5,000,000
Other liabilities				49,000
Total liabilities assumed				100,050,000
Net assets acquired/bargain purchase gain				$ 232,000