XML 16 R1.htm IDEA: XBRL DOCUMENT v3.20.4
COVER - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2020
Feb. 17, 2021
Jun. 30, 2020
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2020    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 0-19065    
Entity Registrant Name SANDY SPRING BANCORP, INC.    
Entity Incorporation, State or Country Code MD    
Entity Tax Identification Number 52-1532952    
Entity Address, Address Line One 17801 Georgia Avenue    
Entity Address, City or Town Olney    
Entity Address, State or Province MD    
Entity Address, Postal Zip Code 20832    
City Area Code 301    
Local Phone Number 774-6400    
Title of 12(b) Security Common Stock, par value $1.00 per share    
Trading Symbol SASR    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 1.1
Entity Common Stock, Shares Outstanding   47,095,833  
Documents Incorporated by Reference
Documents Incorporated By Reference
Part III: Portions of the definitive proxy statement for the Annual Meeting of Shareholders to be held on April 28, 2021 (the "Proxy Statement").
    
Amendment Flag false    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Entity Central Index Key 0000824410