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

Reference 1: 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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the dividend to be paid was declared, 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

Name:	us-gaap_DividendsPayableDateDeclaredDayMonthAndYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

This item represents disclosure of the amount of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporation; these investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities.

+ 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 (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 13

-Article 5

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=cerc_EnableMidstreamPartnersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
	Jul. 22, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Subsequent Event [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions		$ 73	$ 94	$ 145	$ 164
Enable Midstream Partners [Member]
Subsequent Event [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions		$ 73	$ 90	$ 145	$ 157
Enable Midstream Partners [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends Payable, Date Declared	Jul. 22, 2015
Common Stock, Dividends, Per Share, Declared	$ 0.316
Proceeds from Equity Method Investment, Dividends or Distributions	$ 74