Number of shares issued as result of warrant exercises during period.

No definition available.

Name:	cprx_SharesIssuedDuringPeriodWarrantsExercised
Namespace Prefix:	cprx_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	cprx_StockholdersEquityLineItems
Namespace Prefix:	cprx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

Reference 2: 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_DebtConversionConvertedInstrumentAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

+ References

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentSharesIssued1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow associated with the amount received from holders exercising their stock warrants.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=cprx_BiomarinConvertiblePromissoryNoteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stockholders' Equity (Warrant Exercises and BioMarin convertible promissory note automatic conversion into common stock shares) - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 10, 2012
Stockholders' Equity [Line Items]
Issuance of common stock for warrant exercises	1,262,696	3,862,250
Proceeds from exercise of warrants	$ 1,316,503us-gaap_ProceedsFromWarrantExercises	$ 4,083,300us-gaap_ProceedsFromWarrantExercises	$ 16,249us-gaap_ProceedsFromWarrantExercises
Convertible promissory note, principal amount			5,000,000
BioMarin Convertible Promissory Note [Member]
Stockholders' Equity [Line Items]
Conversion price per share				$ 0.75
Convertible promissory note, principal amount				$ 5,000,000
Convertible promissory note shares issued upon conversion				6,666,667