Subsequent Events - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended	0 Months Ended
Apr. 30, 2013	Mar. 29, 2014	Mar. 30, 2013	May 06, 2014 Subsequent Event [Member]
Subsequent Event [Line Items]
Dividend per common share		$ 0.06	$ 0.06	$ 0.06
Dividend declared date				May 06, 2014
Dividend declared payable date				Jun. 18, 2014
Dividend payable, record date				Jun. 06, 2014
Percentage of outstanding common stock available for repurchase	5.00%			5.00%

Maximum percent of outstanding common shares available for repurchase.

No definition available.

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Namespace Prefix:	cot_
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Period Type:	duration

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

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Period Type:	duration

- Definition

Date the declared dividend will be paid, in CCYY-MM-DD format.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

+ Details

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Data Type:	xbrli:dateItemType
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Period Type:	duration

- Definition

Date the dividend to be paid was declared, in CCYY-MM-DD format.

+ References

+ Details

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- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

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- Details

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