Component of Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accrued Liabilities [Line Items]
Clinical consulting services	$ 2,802ziop_AccruedConsultingFeesCurrent	$ 3,751ziop_AccruedConsultingFeesCurrent
Preclinical services	2,027ziop_AccruedPreclinicalServicesCurrent	513ziop_AccruedPreclinicalServicesCurrent
Employee compensation	768	252
Professional services	422us-gaap_AccruedProfessionalFeesCurrent	582us-gaap_AccruedProfessionalFeesCurrent
Payroll taxes and benefits	417us-gaap_AccruedPayrollTaxesCurrent	255us-gaap_AccruedPayrollTaxesCurrent
Manufacturing services	308ziop_AccruedManufacturingCostsCurrent	547ziop_AccruedManufacturingCostsCurrent
Other consulting services	226us-gaap_OtherAccruedLiabilitiesCurrent	230us-gaap_OtherAccruedLiabilitiesCurrent
Accrued vacation	212us-gaap_AccruedVacationCurrent	227us-gaap_AccruedVacationCurrent
Accrued expenses	$ 7,182us-gaap_AccruedLiabilitiesCurrent	$ 6,357us-gaap_AccruedLiabilitiesCurrent

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable for statutory payroll taxes incurred through that date and withheld from employees pertaining to services received from them, including entity's matching share of the employees FICA taxes and contributions to the state and federal unemployment insurance programs. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Current Liabilities

-URI http://asc.fasb.org/extlink&oid=6509677

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6935-107765

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

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

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6911-107765

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable for unused vacation time owed to employees based on the entity's vacation benefit given to its employees. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

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Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations and payables pertaining to claims incurred of a workers compensation nature. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Accrued Consulting Fees, Current

+ References

No definition available.

+ Details

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Namespace Prefix:	ziop_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:	ziop_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Accrued Manufacturing Costs, Current

+ References

No definition available.

+ Details

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Namespace Prefix:	ziop_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Accrued Preclinical Services Current

+ References

No definition available.

+ Details

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Namespace Prefix:	ziop_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant