Debt instrument repurchased premium payment.

No definition available.

Name:	cot_DebtInstrumentRepurchasedPremiumPayment
Namespace Prefix:	cot_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instruments maturity year.

+ References

No definition available.

+ Details

Name:	cot_DebtInstrumentsMaturityYear
Namespace Prefix:	cot_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Write Off Of Unamortized Premium

+ References

No definition available.

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The increase (decrease) during the reporting period in interest payable, which represents the amount owed to note holders, bond holders, and other parties for interest earned on loans or credit extended to the reporting entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

Name:	us-gaap_IncreaseDecreaseInInterestPayableNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=cot_TenPointZeroPercentSeniorNotesDueInTwoThousandTwentyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt (10.000% Senior Notes due in 2021 (the "DSS Notes")) - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended		12 Months Ended
	May 05, 2017	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Aggregate principal amount of redemption		$ 0.3	$ 0.8	$ 101.9	$ 0.9
10.000% Senior Notes Due in 2021 [Member]
Debt Instrument [Line Items]
Aggregate principal amount of redemption	$ 100.0
Premium costs paid on extinguishment of debt	7.7
Accrued interest	$ 1.8
Interest rate on notes	10.00%	10.00%		10.00%
Debt instrument maturity year	2021			2021		2021
Write-off of unamortized premium	$ 9.2