Description of the Business (Details)	9 Months Ended
Description of the Business (Details)	Sep. 30, 2025 USD ($) segment	May 31, 2025 USD ($)	May 23, 2025 USD ($)	Feb. 25, 2025 USD ($)	Dec. 31, 2024 USD ($)	Jun. 21, 2024 USD ($)	Mar. 07, 2024 USD ($)	Feb. 21, 2024 USD ($)	Dec. 03, 2021 USD ($)	Jun. 30, 2021 USD ($)
Description of the Business [Line Items]
Number of reportable segments \| segment	1
Unrestricted cash and cash equivalents	$ 34,292,000				$ 38,648,000
Accumulated deficit	652,790,000				621,864,000
Unsecured Convertible Notes, Due 2026
Description of the Business [Line Items]
Aggregate principal amount									$ 150,000,000.0
Convertible Debt
Description of the Business [Line Items]
Aggregate principal amount										$ 150,000,000.0
Debt instrument, repurchase amount	$ 30,000,000			$ 300,000	$ 120,000,000	$ 300,000	$ 30,900,000	$ 30,900,000
Line of Credit \| Secured Debt \| Asset-Backed Term Loan
Description of the Business [Line Items]
Aggregate principal amount		$ 40,000,000	$ 40,000,000
CM Partners, LLC
Description of the Business [Line Items]
Membership interests acquired (as percent)									100.00%

BuzzFeed, Inc. 10-Q