Segment Reporting - Revenues by Operating Segment and Country (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue, Major Customer [Line Items]
Total revenues	$ 1,375.3	$ 1,208.6	$ 3,972.5	$ 3,341.9
Canada
Revenue, Major Customer [Line Items]
Total revenues	776.6	748.7	2,214.3	2,093.6
United States
Revenue, Major Customer [Line Items]
Total revenues	447.4	310.5	1,318.9	856.1
Other
Revenue, Major Customer [Line Items]
Total revenues	151.3	149.4	439.3	392.2
Tim Hortons brand
Revenue, Major Customer [Line Items]
Total revenues	853.9	827.0	2,440.4	2,332.9
Burger King brand
Revenue, Major Customer [Line Items]
Total revenues	416.4	313.6	1,224.4	874.3
Popeyes brand
Revenue, Major Customer [Line Items]
Total revenues	105.0	$ 68.0	307.7	$ 134.7
Amounts Under Previous Standards
Revenue, Major Customer [Line Items]
Total revenues	1,182.0		3,398.1
Amounts Under Previous Standards | Tim Hortons brand
Revenue, Major Customer [Line Items]
Total revenues	796.5		2,278.6
Amounts Under Previous Standards | Burger King brand
Revenue, Major Customer [Line Items]
Total revenues	315.5		914.5
Amounts Under Previous Standards | Popeyes brand
Revenue, Major Customer [Line Items]
Total revenues	$ 70.0		$ 205.0