Common Shares and Net Income (Loss) per Common Share - Reconciliation (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Numerator:
Net income (loss) attributable to Cott Corporation - Continuing operations	$ 8.5	$ 1.6	$ 25.3	$ (13.1)
Net income (loss) attributable to Cott Corporation - Discontinued operations	1.5	40.9	356.9	(5.4)
Net income (loss) attributable to Cott Corporation	$ 10.0	$ 42.5	$ 382.2	$ (18.5)
Denominator:
Weighted average common shares outstanding - basic (in shares)	138,787	139,205	139,503	138,980
Basic Earnings Per Share:
Continuing operations (usd per share)	$ 0.06	$ 0.01	$ 0.18	$ (0.09)
Discontinued operations (usd per share)	0.01	0.29	2.56	(0.04)
Net income (loss) (usd per share)	$ 0.07	$ 0.30	$ 2.74	$ (0.13)
Denominator:
Weighted average common shares outstanding - basic (in shares)	138,787	139,205	139,503	138,980
Weighted average common shares outstanding - diluted (in shares)	141,176	141,003	141,963	138,980
Continued operations (usd per share)	$ 0.06	$ 0.01	$ 0.18	$ (0.09)
Discontinued operations (usd per share)	0.01	0.29	2.51	(0.04)
Net income (loss) (usd per share)	$ 0.07	$ 0.30	$ 2.69	$ (0.13)
Performance-based RSUs
Denominator:
Dilutive effect (in shares)	918	154	954	0
Time-based RSUs
Denominator:
Dilutive effect (in shares)	259	486	246	0
Stock Options
Denominator:
Dilutive effect (in shares)	1,212	1,158	1,260	0