Company's and Bank's actual capital amounts and ratios (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Capital to risk-weighted assets Company
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Actual Amount	$ 491,239	$ 456,791
Actual Amount	452,473	419,639
Actual Amount	452,473	419,639
Actual Ratio	15.65%	15.40%
Actual Ratio	14.42%	14.15%
Actual Ratio	11.32%	10.98%
For Capital Adequacy Purposes Amount	251,060	237,308
For Capital Adequacy Purposes Amount	125,530	118,654
For Capital Adequacy Purposes Amount	119,939	114,628
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%
Sandy Spring Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Actual Amount	478,023	445,097
Actual Amount	404,258	372,983
Actual Amount	404,258	372,983
Actual Ratio	15.25%	15.02%
Actual Ratio	12.89%	12.59%
Actual Ratio	10.12%	9.77%
For Capital Adequacy Purposes Amount	250,817	237,066
For Capital Adequacy Purposes Amount	125,408	118,533
For Capital Adequacy Purposes Amount	119,866	114,553
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 Prompt Corrective Action Provisions Amount	313,521	296,332
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	188,112	177,799
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 199,777	$ 190,922
To Be Well Capitalized Under Prompt Action Provisions Ratio	10.00%	10.00%
To Be Well Capitalized Under Prompt Action Provisions Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Action Provisions Ratio	5.00%	5.00%