Related Party Transactions - Stockholder Agreement (Details) - Stockholder Agreement	Oct. 29, 2018 item director
Stockholder Agreement
Minimum percentage of outstanding shares of common stock to nominate one member	5.00%
Number of independent director	1
Tengram Stockholders
Stockholder Agreement
Number of members in the Board	8
Percent of outstanding shares to nominate two directors	50.00%
Number of directors nominated on 50% shareholding	2
Percent of outstanding shares to nominate one director	5.00%
Number of directors nominated on 5% shareholding	1
Number of independent directors removed	1
Number of Director appointed by Shareholders \| item	1
GSO Stockholders
Stockholder Agreement
Percent of outstanding shares to nominate two directors	50.00%
Number of directors nominated on 5% shareholding	1
Number of Director appointed by Shareholders \| item	1

Represents the minimum percentage of outstanding shares of common stock to nominate one member.

No definition available.

Name:	ctrc_MinimumPercentageOfOutstandingSharesOfCommonStockToNominateOneMemberRequired
Namespace Prefix:	ctrc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of board of directors.

+ References

No definition available.

+ Details

Name:	ctrc_NumberOfBoardOfDirectors
Namespace Prefix:	ctrc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of director appointed by shareholders in nomination committee.

+ References

No definition available.

+ Details

Name:	ctrc_NumberOfDirectorAppointedInNominationCommitteeByShareholders
Namespace Prefix:	ctrc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of directors who can be nominated on fifty percent shareholding of common stock.

+ References

No definition available.

+ Details

Name:	ctrc_NumberOfDirectorsWhoCanBeNominatedOnFiftyPercentShareholding
Namespace Prefix:	ctrc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of directors who can be nominated on five percent shareholding of common stock.

+ References

No definition available.

+ Details

Name:	ctrc_NumberOfDirectorsWhoCanBeNominatedOnFivePercentShareholding
Namespace Prefix:	ctrc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of independent director in nomination committee.

+ References

No definition available.

+ Details

Name:	ctrc_NumberOfIndependentDirector
Namespace Prefix:	ctrc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of independent directors removed upon written request.

+ References

No definition available.

+ Details

Name:	ctrc_NumberOfIndependentDirectorsRemovedUponWrittenRequest
Namespace Prefix:	ctrc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent stockholders agreement.

+ References

No definition available.

+ Details

Name:	ctrc_StockholderAgreementLineItems
Namespace Prefix:	ctrc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of outstanding shares of common stock of the Company on a fully diluted basis to nominate one director.

+ References

No definition available.

+ Details

Name:	ctrc_ThresholdPercentageOfOutstandingSharesOfCommonStockToNominateOneDirector
Namespace Prefix:	ctrc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of outstanding shares of common stock of the Company on a fully diluted basis to nominate two directors.

+ References

No definition available.

+ Details

Name:	ctrc_ThresholdPercentageOfOutstandingSharesOfCommonStockToNominateTwoDirectors
Namespace Prefix:	ctrc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_TypeOfArrangementAxis=ctrc_StockholderAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=ctrc_TengramStockholdersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=ctrc_GsoStockholdersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: