Consolidated Statement of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash Flows from Operating Activities:
Net Income	$ 21,933	$ 21,892	$ 21,792
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Provision for Loan Losses	845	1,302	1,783
Depreciation and Amortization	6,509	3,563	2,813
Allocation of ESOP Stock	428	453	519
Gains on the Sale of Securities Available-for-Sale	(2,795)	(1,507)	(550)
Losses on the Sale of Securities Available-for-Sale	0	0	193
Other Than Temporary Impairment	0	0	375
Loans Originated and Held-for-Sale	(39,111)	(41,030)	(24,490)
Proceeds from the Sale of Loans Held-for-Sale	49,378	31,760	24,908
Net Gains on the Sale of Loans	(866)	(1,024)	(418)
Net Loss (Gains) on the Sale of Premises and Equipment, Other Real Estate Owned and Repossessed Assets	(32)	10	(2)
Contributions to Pension Plans	(5,319)	(1,813)	(2,304)
Deferred Income Tax Expense (Benefit)	2,172	154	705
Shares Issued Under the Directors' Stock Plan	175	149	116
Stock-Based Compensation Expense	354	299	189
Net Decrease (Increase) in Other Assets	1,725	638	(5,672)
Net (Decrease) Increase in Other Liabilities	689	(4,627)	(625)
Net Cash Provided By Operating Activities	36,085	10,219	19,332
Cash Flows from Investing Activities:
Proceeds from the Sale of Securities Available-for-Sale	39,009	25,497	23,979
Proceeds from the Maturities and Calls of Securities Available-for-Sale	280,126	278,804	112,401
Purchases of Securities Available-for-Sale	(354,310)	(382,614)	(258,026)
Proceeds from the Maturities and Calls of Securities Held-to-Maturity	40,692	15,227	26,772
Purchases of Securities Held-to-Maturity	(31,701)	(6,532)	(61,965)
Net Decrease (Increase) in Loans	3,108	(24,259)	(4,062)
Proceeds from the Sales of Premises and Equipment, Other Real Estate Owned and Repossessed Assets	770	612	1,299
Purchases of Premises and Equipment	(5,372)	(1,081)	(2,501)
Cash Paid for Subsidiaries	(3,296)	264	0
Net Decrease in Other Investments	1,880	333	0
Purchase of Bank Owned Life Insurance	(15,702)	0	0
Net Cash Used In Investing Activities	(44,796)	(93,749)	(162,103)
Cash Flows from Financing Activities:
Net Increase in Deposits	110,042	90,438	168,503
Net (Decrease) Increase in Short-Term Borrowings	15,079	(20,694)	13,952
Federal Home Loan Bank Advances	10,000	10,000	0
Federal Home Loan Bank Repayments	(100,000)	(20,000)	(20,000)
Purchases of Treasury Stock	(6,039)	(3,347)	(3,761)
Stock Options Exercised	1,413	798	1,178
Shares Issued Under the Employee Stock Purchase Plan	474	475	466
Tax Benefit from Exercise of Stock Options	51	105	193
Shares Issued for Dividend Reinvestment Plans	1,796	1,715	1,658
Acquisition by ESOP of Arrow Stock	0	(1,000)	0
Cash Dividends Paid	(11,448)	(10,997)	(10,640)
Net Cash Provided By Financing Activities	21,368	47,493	151,549
Net Increase (Decrease) in Cash and Cash Equivalents	12,657	(36,037)	8,778
Cash and Cash Equivalents at Beginning of Year	31,079	67,116	58,338
Cash and Cash Equivalents at End of Year	43,736	31,079	67,116
Supplemental Disclosures to Statements of Cash Flow Information:
Interest on Deposits and Borrowings	19,490	23,995	27,201
Income Taxes	7,952	15,223	10,301
Non-cash Investing and Financing Activities:
Transfer of Loans to Other Real Estate Owned and Repossessed Assets	1,011	568	683
Shares Issued for Acquisition of Subsidiary	5,261	682	542
Fair Value of Assets from Acquisition of Subsidiary	10,638	882	0
Fair Value of Liabilities from Acquisition of Subsidiary	$ 2,081	$ 465	$ 0