Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Thousands				3 Months Ended	9 Months Ended	27 Months Ended
	May 23, 2025 USD ($) $ / shares shares	Jun. 20, 2023 shares	Mar. 21, 2023 USD ($)	Jun. 30, 2025 USD ($)	Sep. 30, 2025 USD ($) $ / shares shares	Sep. 30, 2025 USD ($) $ / shares shares	Dec. 31, 2024 $ / shares shares	Jul. 31, 2024 USD ($)	Dec. 03, 2021 vote $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Preferred stock, shares authorized (in shares)									50,000,000
Preferred stock, par value per share (in dollars per share) \| $ / shares									$ 0.0001
Preferred stock, shares issued (in shares)					0	0	0
Preferred stock, shares outstanding (in shares)					0	0	0
Share repurchase program, authorized, number of shares (in shares)	1,800,000
Purchase price (in dollars per share) \| $ / shares	$ 1.82
Aggregate purchase price \| $	$ 3,300			$ 3,332
Shares repurchased (in shares)	1,800,000
Stock-based compensation cost not yet recognized, options \| $					$ 4,800	$ 4,800
Sale of stock, equity issuable, amount \| $			$ 150,000
ATM Offering Agreement
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Sale of stock, equity distribution agreement, maximum offering (in shares)		3,316,503
Sale of stock, increase in aggregate offering price \| $								$ 150,000
Number of shares issued (in shares)						1,153,345
Issue price (in dollars per share) \| $ / shares					$ 2.52	$ 2.52
Aggregate net proceeds after deducting commissions and offering expenses \| $						$ 2,800
Stock Option
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Weighted-average remaining requisite service period (in years)					9 months 18 days
Restricted Stock Units
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unrecognized compensation costs \| $					$ 5,200	$ 5,200
Common Stock – Class A
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock, shares authorized (in shares)					700,000,000	700,000,000	700,000,000		700,000,000
Common stock, par value (in dollars per share) \| $ / shares	$ 0.0001				$ 0.0001	$ 0.0001	$ 0.0001		$ 0.0001
Common shares, votes per share (in vote per share) \| vote									1
Common Stock – Class B
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock, shares authorized (in shares)					20,000,000	20,000,000	20,000,000		20,000,000
Common stock, par value (in dollars per share) \| $ / shares					$ 0.0001	$ 0.0001	$ 0.0001		$ 0.0001
Common shares, votes per share (in vote per share) \| vote									50
Common Stock – Class C
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock, shares authorized (in shares)									10,000,000
Common stock, par value (in dollars per share) \| $ / shares									$ 0.0001
Common shares, votes per share (in vote per share) \| vote									0

BuzzFeed, Inc. 10-Q