Share-based Compensation - Share-based Compensation Expense (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation expense from discontinued operations	$ 5.4	$ 2.4	$ 2.7

Allocated share based compensation expense discontinued operations.

No definition available.

Name:	cot_AllocatedShareBasedCompensationExpenseDiscontinuedOperations
Namespace Prefix:	cot_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration