Segment Information - Reconciliation of Revenues and Operating Measures from Segments to Consolidated (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2026	Mar. 31, 2025
Segment Reporting [Line Items]
Revenues		$ 429.6	$ 390.7
Operating		(227.5)	(221.3)
Selling, General and Administrative Expense	[1]	(107.3)	(114.7)
Adjusted OIBDA		100.4	64.2
Operating income		55.9	13.9
Net loss on dispositions		(1.0)	(0.1)
Depreciation		(20.7)	(23.6)
Amortization		(17.2)	(17.1)
Stock-based compensation		(5.6)	(9.5)
Interest expense, net		(36.0)	(36.0)
Income (loss) before provision for income taxes and equity in earnings of investee companies		19.9	(22.1)
Provision for income taxes		(0.4)	(0.5)
Equity in earnings of investee companies, net of tax		(0.2)	1.9
Net income (loss) before allocation to redeemable and non-redeemable noncontrolling interests		19.3	(20.7)
Net income (loss) attributable to redeemable and non-redeemable noncontrolling interests		0.2	(0.1)
Net income (loss) attributable to OUTFRONT Media Inc.		19.1	(20.6)
Stock-based compensation		5.6	9.5
Billboard Property Lease
Segment Reporting [Line Items]
Operating	[2]	(111.3)	(109.2)
Transit Franchise
Segment Reporting [Line Items]
Operating	[2]	(59.7)	(58.0)
Posting Maintenance And Other
Segment Reporting [Line Items]
Operating	[2]	(56.5)	(54.1)
Operating segments
Segment Reporting [Line Items]
Revenues		427.9	388.4
Operating	[2]	(226.0)	(219.5)
Selling, General and Administrative Expense	[1]	(86.9)	(84.1)
Adjusted OIBDA		115.0	84.8
Operating segments | Billboard Property Lease
Segment Reporting [Line Items]
Operating	[2]	(111.3)	(109.2)
Operating segments | Transit Franchise
Segment Reporting [Line Items]
Operating	[2]	(59.7)	(58.0)
Operating segments | Posting Maintenance And Other
Segment Reporting [Line Items]
Operating	[2]	(55.0)	(52.3)
Operating segments | Billboard Operating Segment
Segment Reporting [Line Items]
Revenues		332.9	310.7
Operating	[2]	(148.4)	(144.9)
Selling, General and Administrative Expense	[1]	(68.1)	(66.8)
Adjusted OIBDA		$ 116.4	$ 99.0
Segment Adjusted OIBDA Margin		35.00%	31.90%
Operating segments | Billboard Operating Segment | Billboard Property Lease
Segment Reporting [Line Items]
Operating	[2]	$ (111.3)	$ (109.2)
Operating segments | Billboard Operating Segment | Posting Maintenance And Other
Segment Reporting [Line Items]
Operating	[2]	(37.1)	(35.7)
Operating segments | Transit Operating Segment
Segment Reporting [Line Items]
Revenues		95.0	77.7
Operating	[2]	(77.6)	(74.6)
Selling, General and Administrative Expense	[1]	(18.8)	(17.3)
Adjusted OIBDA		$ (1.4)	$ (14.2)
Segment Adjusted OIBDA Margin		(1.50%)	(18.30%)
Operating segments | Transit Operating Segment | Transit Franchise
Segment Reporting [Line Items]
Operating	[2]	$ (59.7)	$ (58.0)
Operating segments | Transit Operating Segment | Posting Maintenance And Other
Segment Reporting [Line Items]
Operating	[2]	(17.9)	(16.6)
Corporate and Reconciling Items
Segment Reporting [Line Items]
Adjusted OIBDA		$ (14.6)	$ (20.6)

[1] Selling, general and administrative expenses includes, but is not limited to, compensation and benefits, including commissions, professional fees, office rent and travel and entertainment.

[2] The significant expense categories and amounts align with the segment-level information that is regularly provided to the chief operating decision maker.