Annual report pursuant to Section 13 and 15(d)

Cover Page

v3.19.3.a.u2
Cover Page - USD ($)
12 Months Ended
Dec. 31, 2019
Jan. 31, 2020
Jun. 28, 2019
Cover page.      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2019    
Document Transition Report false    
Entity File Number 000-26427    
Entity Registrant Name Stamps.com Inc    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 77-0454966    
Entity Address, Address Line One 1990 E. Grand Avenue    
Entity Address, City or Town El Segundo    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 90245    
City Area Code 310    
Local Phone Number 482-5800    
Title of 12(b) Security Common Stock, $.001 par value    
Trading Symbol STMP    
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    
Entity Shell Company false    
Entity Public Float     $ 745,913,835
Entity Common Stock, Shares Outstanding   17,056,278  
Entity Central Index Key 0001082923    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Amendment Flag false