Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Interest and dividend income:
Interest and fees on loans	$ 32,874	$ 31,481
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	4,309	4,524
Interest on held to maturity securities:
Total interest on held to maturity securities	779	1,101
Federal Reserve Bank and Federal Home Loan Bank stock	133	119
Interest on federal funds sold and other short-term investments	351	245
Total interest and dividend income	38,446	37,470
Interest expense:
Interest-bearing checking	84	80
Savings	763	916
Money market deposit accounts	599	685
Time deposits	1,951	1,820
Interest on short-term borrowings	393	364
Total interest expense	3,790	3,865
Net interest income	34,656	33,605
Provision for loan losses	1,500	2,000
Net interest income after provision for loan losses	33,156	31,605
Noninterest income:
Trustco financial services income	1,510	1,421
Fees for services to customers	2,521	2,887
Net gain on securities transactions	6	2
Other	1,722	282
Total noninterest income	5,759	4,592
Noninterest expenses:
Salaries and employee benefits	7,592	8,178
Net occupancy expense	4,259	4,053
Equipment expense	1,752	1,718
Professional services	1,286	1,420
Outsourced services	1,325	1,350
Advertising expense	599	730
FDIC and other insurance	904	1,010
Other real estate expense, net	855	749
Other	2,229	2,349
Total noninterest expenses	20,801	21,557
Income before taxes	18,114	14,640
Income taxes	7,103	5,472
Net income	11,011	9,168
Net income per Common Share:
Basic (in dollars per share)	$ 0.116	$ 0.097
Diluted (in dollars per share)	$ 0.116	$ 0.097
U. S. government sponsored enterprises [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	506	816
Interest on held to maturity securities:
Total interest on held to maturity securities	0	0
State and political subdivisions [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	68	191
Mortgage-backed securities and collateralized mortgage obligations-residential [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	3,078	2,769
Interest on held to maturity securities:
Total interest on held to maturity securities	625	789
Corporate bonds [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	59	218
Interest on held to maturity securities:
Total interest on held to maturity securities	154	312
Small Business Administration-guaranteed participation securities [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	556	496
Mortgage-backed securities and collateralized mortgage obligations-Commercial [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	38	29
Other securities [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	$ 4	$ 5