Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Assets:
Cash and due from banks	$ 84,682	$ 93,150
Cash at Federal Reserve and other banks	196,546	517,578
Cash and cash equivalents	281,228	610,728
Investment securities:
Available for sale	225,126	83,205
Held to maturity	802,482	676,426
Restricted equity securities	16,956	16,956
Loans held for sale	5,413	3,579
Loans	2,320,883	2,282,524
Allowance for loan losses	(36,055)	(36,585)
Total loans, net	2,284,828	2,245,939
Foreclosed assets, net	5,892	4,894
Premises and equipment, net	42,846	43,493
Cash value of life insurance	93,012	92,337
Accrued interest receivable	9,794	9,275
Goodwill	63,462	63,462
Other intangible assets, net	6,762	7,051
Mortgage servicing rights	7,057	7,378
Other assets	51,002	51,735
Total assets	3,895,860	3,916,458
Deposits:
Noninterest-bearing demand	1,034,012	1,083,900
Interest-bearing	2,315,476	2,296,523
Total deposits	3,349,488	3,380,423
Accrued interest payable	852	978
Reserve for unfunded commitments	2,015	2,145
Other liabilities	53,256	49,192
Other borrowings	9,096	9,276
Junior subordinated debt	56,320	56,272
Total liabilities	3,471,027	3,498,286
Commitments and contingencies (Note 18)
Shareholders' equity:
Common stock, no par value: 50,000,000 shares authorized; issued and outstanding: 22,740,503 at March 31, 2015 22,714,964 at December 31, 2014	245,316	244,318
Retained earnings	181,600	176,057
Accumulated other comprehensive loss, net of tax	(2,083)	(2,203)
Total shareholders' equity	424,833	418,172
Total liabilities and shareholders' equity	$ 3,895,860	$ 3,916,458