Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions		3 Months Ended									12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018		Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues [Abstract]
Billboard											$ 1,189.9	$ 1,112.4	$ 1,059.0
Transit and other											592.3	493.8	461.5
Total revenues		$ 488.1	$ 462.5	$ 459.9	$ 371.7	$ 452.4	$ 414.2	$ 401.7		$ 337.9	1,782.2	1,606.2	1,520.5
Expenses:
Operating											958.6	859.9	835.2
Selling, general and administrative											323.5	287.0	261.7
Restructuring charges											0.3	2.1	6.4
Net gain on dispositions		(0.8)	(1.9)	0.4	(1.5)	(1.3)	(1.3)	(2.7)		(0.2)	(3.8)	(5.5)	(14.3)
Impairment charge						0.0	0.0	42.9	[1]	0.0	0.0	42.9	0.0
Depreciation		22.4	22.4	21.4	21.1	22.5	21.0	21.3		21.1	87.3	85.9	89.7
Amortization		26.2	28.7	27.6	24.7	25.8	25.8	25.0		22.5	107.2	99.1	100.1
Total expenses											1,473.1	1,371.4	1,278.8
Operating income		98.0	85.5	88.7	36.9	91.3	78.9	32.9		31.7	309.1	234.8	241.7
Interest expense, net											(134.9)	(125.7)	(116.9)
Loss on extinguishment of debt											(28.5)	0.0	0.0
Other income (expense), net											0.1	(0.4)	0.3
Income before provision for income taxes and equity in earnings of investee companies											145.8	108.7	125.1
Provision for income taxes											(10.9)	(4.9)	(4.1)
Equity in earnings of investee companies, net of tax											5.7	4.1	4.8
Net income before allocation to non-controlling interests											140.6	107.9	125.8
Net income attributable to non-controlling interests											0.5	0.0	0.0
Net income attributable to OUTFRONT Media Inc.		$ 45.0	$ 38.7	$ 50.3	$ 6.1	$ 57.2	$ 46.8	$ (5.2)		$ 9.1	$ 140.1	$ 107.9	$ 125.8
Net income per common share:
Basic ($ per share)		$ 0.31	$ 0.27	$ 0.35	$ 0.04	$ 0.40	$ 0.33	$ (0.04)		$ 0.06	$ 0.97	$ 0.76	$ 0.90
Diluted ($ per share)		$ 0.31	$ 0.27	$ 0.35	$ 0.04	$ 0.40	$ 0.33	$ (0.04)		$ 0.06	$ 0.97	$ 0.75	$ 0.90
Weighted average shares outstanding:
Basic (shares)											142.5	139.3	138.5
Diluted (shares)	[2],[3]										143.2	139.6	138.9

[1] As a result of an impairment analysis performed during the second quarter of 2018, we determined that the carrying value of our Canadian reporting unit exceeded its fair value and we recorded an impairment charge of $42.9 million on the Consolidated Statement of Operations. See Note 6. Goodwill and Other Intangible Assets: Goodwill to the Consolidated Financial Statements

[2] The potential impact of an aggregate 0.1 million granted RSUs, PRSUs and stock options for 2019, 0.4 million granted RSUs, PRSUs and stock options for 2018 and 0.1 million granted RSUs, PRSUs and stock options for 2017 was antidilutive.

[3] On June 13, 2017, 1,953,407 shares of Class A equity interests of Outfront Canada were issued, which may be redeemed by the holders in exchange for shares of the Company’s common stock on a one-for-one basis (subject to anti-dilution adjustments), at our option, after a certain time period. (See Note 11. Equity to the Consolidated Financial Statements.) The potential impact of 1.4 million shares of Class A equity interests of Outfront Canada was antidilutive for 2019, 1.9 million shares of Class A equity interests of Outfront Canada was antidilutive for 2018 and 1.1 million shares of Class A equity interests of Outfront Canada was antidilutive for 2017.