Company's and Bank's actual capital amounts and ratios (Detail) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Capital to risk-weighted assets Company
Actual Amount	$ 456,791,000	$ 419,780,000
Actual Amount	419,639,000	386,423,000
Actual Amount	419,639,000	386,423,000
Actual Ratio	15.40%	15.83%
Actual Ratio	14.15%	14.57%
Actual Ratio	10.98%	10.84%
For Capital Adequacy Purposes Amount	237,308,000	212,199,000
For Capital Adequacy Purposes Amount	118,654,000	106,099,000
For Capital Adequacy Purposes Amount	114,628,000	106,976,000
For Capital Adequacy Purposes Ratio	8.00%	8.00%
For Capital Adequacy Purposes Ratio	4.00%	4.00%
For Capital Adequacy Purposes Ratio	3.00%	3.00%
To Be Well Capitalized Under Capitalized Under Action Provisions Amount	0	0
To Be Well Capitalized Under Capitalized Under Action Provisions Amount	0	0
To Be Well Capitalized Under Capitalized Under Action Provisions Amount	0	0
To Be Well Capitalized Under Capitalized Under Action Provisions Ratio	0.00%	0.00%
To Be Well Capitalized Under Capitalized Under Action Provisions Ratio	0.00%	0.00%
To Be Well Capitalized Under Capitalized Under Action Provisions Ratio	0.00%	0.00%
Sandy Spring Bank
Actual Amount	445,097,000	397,526,000
Actual Amount	372,983,000	329,197,000
Actual Amount	372,983,000	329,197,000
Actual Ratio	15.02%	15.00%
Actual Ratio	12.59%	12.42%
Actual Ratio	9.77%	9.24%
For Capital Adequacy Purposes Amount	237,066,000	212,016,000
For Capital Adequacy Purposes Amount	118,533,000	106,008,000
For Capital Adequacy Purposes Amount	114,553,000	106,920,000
For Capital Adequacy Purposes Ratio	8.00%	8.00%
For Capital Adequacy Purposes Ratio	4.00%	4.00%
For Capital Adequacy Purposes Ratio	3.00%	3.00%
To Be Well Capitalized Under Capitalized Under Action Provisions Amount	296,332,000	265,021,000
To Be Well Capitalized Under Capitalized Under Action Provisions Amount	177,799,000	159,012,000
To Be Well Capitalized Under Capitalized Under Action Provisions Amount	$ 190,922,000	$ 178,200,000
To Be Well Capitalized Under Capitalized Under Action Provisions Ratio	10.00%	10.00%
To Be Well Capitalized Under Capitalized Under Action Provisions Ratio	6.00%	6.00%
To Be Well Capitalized Under Capitalized Under Action Provisions Ratio	5.00%	5.00%