XML 67 R44.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stockholders' Equity - Additional Information (Detail) - USD ($) |  | 1 Months Ended | 3 Months Ended |
--- | --- | --- | --- | ---
Jan. 08, 2018 | Jan. 31, 2018 | Mar. 31, 2018 | May 05, 2016
Amendment No. 2 | Cantor | Sales Agreement |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Maximum common stock offering price |  |  | $ 132,200,000 |
Common stock registered for sale |  |  |  | $ 70,000,000
Amendment No. 3 | Cantor | Sales Agreement |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Maximum common stock offering price | $ 70,000,000 |  |  |
Common stock registered for sale |  |  | $ 70,000,000 |
Percentage of proceeds payable as compensation to underwriter | 2.00% |  |  |
Unsold shares of common stock, value | $ 31,400,000 |  |  |
Common stock, number of shares issued |  |  | 9,300 |
Amendment No. 3 | Cantor | Sales Agreement | Maximum |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Proceeds from common stock sold |  |  | $ 100,000 |
Common Stock | Underwritten Public Offering |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Common stock, shares issued and sold |  | 14,030,000 |  |
Common stock, par value |  | $ 0.001 |  |
Common stock, sale of stock, price per share |  | $ 4.10 |  |
Proceeds from common stock sold |  | $ 57,200,000 |  |

X
- Definition Common Stock, Shares Available for Sale, Value + References No definition available. + Details
Name: | cers_CommonStockSharesAvailableForSaleValue
Namespace Prefix: | cers_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Common stock shares unsold value. + References No definition available. + Details
Name: | cers_CommonStockSharesUnsoldValue
Namespace Prefix: | cers_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Maximum amount available under ATM offering. + References No definition available. + Details
Name: | cers_MaximumAmountAvailableUnderOffering
Namespace Prefix: | cers_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of proceeds payable as compensation to underwriter. + References No definition available. + Details
Name: | cers_PercentageOfProceedsPayableAsCompensationToUnderwriter
Namespace Prefix: | cers_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Stockholders Equity Note [Line Items] + References No definition available. + Details
Name: | cers_StockholdersEquityNoteLineItems
Namespace Prefix: | cers_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face amount or stated value per share of common stock. + 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of new stock issued during the period. + 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644 Reference 3: 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: 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
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=cers_SalesAmendmentTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CounterpartyNameAxis=cers_CantorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=cers_SalesAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=cers_SalesAmendmentThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=cers_UnderwrittenPublicOfferingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |