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

Amount of the fee that accompanies borrowing money under the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: 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(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentFeeAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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=31042434&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 incremental, external costs directly pertaining to an early extinguishment of debt, including legal costs and prepayment penalties, and excluding interest and repayment of debt principal.

+ References

No definition available.

+ Details

Name:	us-gaap_PaymentsOfDebtExtinguishmentCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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=31042434&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.8)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

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

- Details

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

Debt (8.125% Senior Notes due in 2018) - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended		3 Months Ended		0 Months Ended
	Feb. 19, 2014	Nov. 15, 2013	Apr. 04, 2015	Mar. 29, 2014	Jul. 09, 2014	Jun. 24, 2014	Aug. 17, 2010
Debt Instrument [Line Items]
Aggregate principal amount of redemption			$ 0.8us-gaap_RepaymentsOfLongTermDebt	$ 16.0us-gaap_RepaymentsOfLongTermDebt
Deferred financing fees	0.3	4.0		0.3
Other costs		0.5
8.125% Senior Notes Due in 2018 [Member]
Debt Instrument [Line Items]
Financing fees							8.6
Aggregate principal amount of redemption					79.1	295.9
Premium costs paid on extinguishment of debt					3.8	16.2
Accrued interest					2.5	7.5
Deferred financing fees					0.8	3.0
Other costs						$ 0.2