Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (USD $) In Thousands	Total	Common Stock	Additional Paid-in Capital (In thousands, except per share data)	Retained Earnings (In thousands, except per share data)	Accumulated Other Comprehensive Loss (In thousands, except per share data)
Beginning balance at Dec. 31, 2009	$ 474,311	$ 23,891	$ 347,676	$ 115,391	$ (12,647)
Comprehensive Income:
Net Income	15,551			15,551
Other:
Net unrealized gains on investment securities--available-for-sale, net of tax expense of $782 and $139 in 2010 and 2011 respectively					1,452
Adjustment for pension and other postretirement benefits, net of tax expense of $44 and $189 in 2010 and 2011 respectively					82
Comprehensive income	17,085
Shares issued - stock options	42	1	41
Shares and stock options issued in the acquisition of O.A.K. Financial Corporation	83,697	3,530	80,167
Cash dividends declared of $0.60 per share	(15,755)			(15,755)
Shares issued - directors' stock plans	250	12	238
Share-based compensation	1,343	6	1,337
Ending balance at Sep. 30, 2010	560,973
Beginning balance at Dec. 31, 2010	560,078	27,440	429,511	117,238	(14,111)
Comprehensive Income:
Net Income	31,846			31,846
Other:
Net unrealized gains on investment securities--available-for-sale, net of tax expense of $782 and $139 in 2010 and 2011 respectively					259
Adjustment for pension and other postretirement benefits, net of tax expense of $44 and $189 in 2010 and 2011 respectively					351
Comprehensive income	32,456
Cash dividends declared of $0.60 per share	(16,473)			(16,473)
Shares issued - directors' stock plans	266	12	254
Share-based compensation	702	5	697
Ending balance at Sep. 30, 2011	$ 577,029	$ 27,457	$ 430,462	$ 132,611	$ (13,501)