Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Interest and dividend income:
Interest and fees on loans	$ 32,277	$ 32,184	$ 64,702	$ 63,861
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	5,140	6,223	9,864	12,014
Interest on held to maturity securities:
Total interest on held to maturity securities	1,585	1,835	3,409	3,738
Interest on federal funds sold and other short-term investments	299	254	619	500
Total interest income	39,301	40,496	78,594	80,113
Interest on deposits:
Interest-bearing checking	78	70	156	135
Savings	979	885	2,081	1,818
Money market deposit accounts	770	1,184	1,693	2,411
Time deposits	3,230	4,099	6,648	8,542
Interest on short-term borrowings	378	382	766	789
Total interest expense	5,435	6,620	11,344	13,695
Net interest income	33,866	33,876	67,250	66,418
Provision for loan losses	3,000	4,850	6,100	9,450
Net interest income after provision for loan losses	30,866	29,026	61,150	56,968
Noninterest income:
Trustco financial services income	1,407	1,186	2,801	2,760
Fees for services to customers	2,388	2,325	4,628	4,419
Net gain on securities transactions	55	851	732	1,138
Other	176	209	383	525
Total noninterest income	4,026	4,571	8,544	8,842
Noninterest expenses:
Salaries and employee benefits	7,519	7,000	15,262	14,026
Net occupancy expense	3,817	3,672	7,612	7,409
Equipment expense	1,600	1,481	3,120	2,813
Professional services	1,489	1,681	2,925	3,166
Outsourced services	1,347	1,350	2,597	2,700
Advertising expense	1,060	708	1,869	1,414
FDIC and other insurance	953	1,392	1,833	3,243
Other real estate expense, net	665	2,095	1,631	3,685
Other	2,048	2,173	4,293	3,942
Total noninterest expenses	20,498	21,552	41,142	42,398
Income before taxes	14,394	12,045	28,552	23,412
Income taxes	5,328	4,279	10,577	8,264
Net income	9,066	7,766	17,975	15,148
Net income per Common Share:
Basic (in dollars per share)	$ 0.097	$ 0.100	$ 0.192	$ 0.196
Diluted (in dollars per share)	$ 0.097	$ 0.100	$ 0.192	$ 0.196
U. S. government sponsored enterprises [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	2,606	3,791	4,910	6,990
Interest on held to maturity securities:
Total interest on held to maturity securities	0	0	25	0
State and political subdivisions [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	368	640	778	1,424
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	1,364	622	2,457	1,230
Interest on held to maturity securities:
Total interest on held to maturity securities	1,198	1,240	2,488	2,428
Corporate bonds [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	648	1,081	1,470	2,220
Interest on held to maturity securities:
Total interest on held to maturity securities	387	595	896	1,310
Other securities [Member]
Interest and dividends on securities available for sale:
Total interest and dividends on securities available for sale	$ 154	$ 89	$ 249	$ 150