Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions	Total	Series A Preferred Stock	Common stock	Series A Preferred Stock	Common stock	Additional Paid-In Capital	Distribution in Excess of Earnings	Distribution in Excess of Earnings Series A Preferred Stock	Distribution in Excess of Earnings Common stock	Accumulated Other Comprehensive Loss	Noncontrolling Interest	At-The-Market Equity Offering Program	At-The-Market Equity Offering Program Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of a new accounting standard	$ (24.8)						$ (24.8)
Total equity, beginning of period at Dec. 31, 2018	1,145.3
Shares of common stock, beginning balance at Dec. 31, 2018					140,200,000
Total stockholders' equity, beginning balance at Dec. 31, 2018					$ 1.4	$ 1,995.0	(871.6)			$ (22.0)
Total stockholders' equity, beginning balance at Dec. 31, 2018	1,102.8
Non-controlling interests, beginning balance at Dec. 31, 2018											$ 42.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to OUTFRONT Media Inc.	56.4						56.4
Net income (loss) attributable to non-controlling interests	0.0
Net income (loss) before allocation to non-controlling interests	56.4
Other comprehensive income (loss)	4.3									4.3
Other comprehensive income (loss) - total equity	4.3
Stock-based payments: Vested (shares)					900,000
Stock-based payments: Amortization	10.8					10.8
Shares paid for tax withholding for stock-based payments (shares)					(400,000)
Shares paid for tax withholding for stock-based payments	(7.7)					(7.7)
Class A equity interest redemptions (shares)					400,000
Class A equity interest redemptions	8.9					8.9
Decrease in non-controlling interests due to redemptions											(8.9)
Shares issued under the ATM Program (shares)					2,200,000
Shares issued under the ATM Program												$ 50.8	$ 50.8
Dividends	(103.9)						(103.9)
Non-Controlling Interests - Other											3.6
Other	0.1					0.1
Other	3.7
Shares of common stock, ending balance at Jun. 30, 2019					143,300,000
Total stockholders' equity, ending balance at Jun. 30, 2019					$ 1.4	2,057.9	(943.9)			(17.7)
Total stockholders' equity, ending balance at Jun. 30, 2019	1,097.7
Non-controlling interests, ending balance at Jun. 30, 2019											37.2
Total equity, end of period at Jun. 30, 2019	1,134.9
Total equity, beginning of period at Mar. 31, 2019	1,091.9
Shares of common stock, beginning balance at Mar. 31, 2019					141,600,000
Total stockholders' equity, beginning balance at Mar. 31, 2019					$ 1.4	2,012.0	(941.9)			(20.2)
Total stockholders' equity, beginning balance at Mar. 31, 2019	1,051.3
Non-controlling interests, beginning balance at Mar. 31, 2019											40.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to OUTFRONT Media Inc.	50.3						50.3
Net income (loss) attributable to non-controlling interests	0.0
Net income (loss) before allocation to non-controlling interests	50.3
Other comprehensive income (loss)	2.5									2.5
Other comprehensive income (loss) - total equity	2.5
Stock-based payments: Amortization	5.5					5.5
Class A equity interest redemptions (shares)					300,000
Class A equity interest redemptions	6.1					6.1
Decrease in non-controlling interests due to redemptions											(6.1)
Shares issued under the ATM Program (shares)					1,400,000
Shares issued under the ATM Program												$ 34.3	$ 34.3
Dividends	(52.3)						(52.3)
Non-Controlling Interests - Other											2.7
Other	0.0					0.0
Other	2.7
Shares of common stock, ending balance at Jun. 30, 2019					143,300,000
Total stockholders' equity, ending balance at Jun. 30, 2019					$ 1.4	2,057.9	(943.9)			(17.7)
Total stockholders' equity, ending balance at Jun. 30, 2019	1,097.7
Non-controlling interests, ending balance at Jun. 30, 2019											37.2
Total equity, end of period at Jun. 30, 2019	1,134.9
Series A Preferred Stock outstanding (shares), beginning balance at Dec. 31, 2019				0
Series A Preferred Stock, beginning balance at Dec. 31, 2019	0.0			$ 0.0
Total equity, beginning of period at Dec. 31, 2019	$ 1,126.4
Shares of common stock, beginning balance at Dec. 31, 2019	143,600,000				143,600,000
Total stockholders' equity, beginning balance at Dec. 31, 2019					$ 1.4	2,074.7	(964.6)			(17.7)
Total stockholders' equity, beginning balance at Dec. 31, 2019	$ 1,093.8
Non-controlling interests, beginning balance at Dec. 31, 2019	32.6										32.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to OUTFRONT Media Inc.	(51.8)						(51.8)
Net income (loss) attributable to non-controlling interests	0.1
Net income (loss) before allocation to non-controlling interests	(51.7)
Other comprehensive income (loss)	(9.2)									(9.2)
Other comprehensive income (loss) - total equity	(9.2)
Stock-based payments: Vested (shares)					1,000,000.0
Stock-based payments: Amortization	11.9					11.9
Shares paid for tax withholding for stock-based payments (shares)					(400,000)
Shares paid for tax withholding for stock-based payments	(12.2)					(12.2)
New share issues (shares)				400,000
New share issues	383.4			$ 383.4
Class A equity interest redemptions (shares)					200,000
Class A equity interest redemptions	$ 4.4					4.4
Decrease in non-controlling interests due to redemptions											(4.4)
Shares issued under the ATM Program (shares)												0
Dividends		$ (5.5)	$ (55.3)					$ (5.5)	$ (55.3)
Non-Controlling Interests - Other											(1.1)
Series A Preferred Stock outstanding (shares), ending balance at Jun. 30, 2020	400,000			400,000
Series A Preferred Stock, ending balance at Jun. 30, 2020	$ 383.4			$ 383.4
Shares of common stock, ending balance at Jun. 30, 2020	144,400,000				144,400,000
Total stockholders' equity, ending balance at Jun. 30, 2020					$ 1.4	2,078.8	(1,077.2)			(26.9)
Total stockholders' equity, ending balance at Jun. 30, 2020	$ 976.1
Non-controlling interests, ending balance at Jun. 30, 2020	27.2										27.2
Total equity, end of period at Jun. 30, 2020	1,386.7
Series A Preferred Stock outstanding (shares), beginning balance at Mar. 31, 2020				0
Series A Preferred Stock, beginning balance at Mar. 31, 2020				$ 0.0
Total equity, beginning of period at Mar. 31, 2020	1,057.0
Shares of common stock, beginning balance at Mar. 31, 2020					144,400,000
Total stockholders' equity, beginning balance at Mar. 31, 2020					$ 1.4	2,072.8	(1,013.8)			(31.8)
Total stockholders' equity, beginning balance at Mar. 31, 2020	1,028.6
Non-controlling interests, beginning balance at Mar. 31, 2020											28.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to OUTFRONT Media Inc.	(57.9)						(57.9)
Net income (loss) attributable to non-controlling interests	(0.1)
Net income (loss) before allocation to non-controlling interests	(58.0)
Other comprehensive income (loss)	4.9									4.9
Other comprehensive income (loss) - total equity	4.9
Stock-based payments: Amortization	6.1					6.1
Shares paid for tax withholding for stock-based payments	(0.1)					(0.1)
New share issues (shares)				400,000
New share issues	383.4			$ 383.4
Shares issued under the ATM Program (shares)												0
Dividends		$ (5.5)						$ (5.5)
Non-Controlling Interests - Other											(1.1)
Other	$ (1.1)
Series A Preferred Stock outstanding (shares), ending balance at Jun. 30, 2020	400,000			400,000
Series A Preferred Stock, ending balance at Jun. 30, 2020	$ 383.4			$ 383.4
Shares of common stock, ending balance at Jun. 30, 2020	144,400,000				144,400,000
Total stockholders' equity, ending balance at Jun. 30, 2020					$ 1.4	$ 2,078.8	$ (1,077.2)			$ (26.9)
Total stockholders' equity, ending balance at Jun. 30, 2020	$ 976.1
Non-controlling interests, ending balance at Jun. 30, 2020	27.2										$ 27.2
Total equity, end of period at Jun. 30, 2020	$ 1,386.7