Represents the term of a consulting agreement.

No definition available.

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Namespace Prefix:	bcda_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the length of time of each of the automatic renewal periods for the term of a consulting agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	bcda_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of the entity that is owned by a specified related party.

+ References

No definition available.

+ Details

Name:	bcda_RelatedPartyOwnershipPercentage
Namespace Prefix:	bcda_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Grant-date fair value of non-vested options outstanding.

+ References

No definition available.

+ Details

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

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

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

- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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

- Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=bcda_ConsultingServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Note 10 - Related Party Transactions (Details Textual) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross				1,698,452
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance		$ 2.80		$ 2.80		$ 2.96
Allocated Share-based Compensation Expense, Total		$ 730,000	$ 701,000	$ 2,083,000	$ 1,999,000
OPKO [Member]
Related Party, Ownership Percentage	5.00%
OPKO [Member] \| Consulting Services [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	418,977
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance	$ 1.80
Allocated Share-based Compensation Expense, Total				121,000	$ 432,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Grant Date Fair Value		$ 5,300,000		$ 5,300,000
Consulting Agreement, Term	4 years
Consulting Agreement, Term, Length of Automatic Renewal Periods	1 year
Chairman and Chief Executive Officer of OPKO [Member]
Related Party, Ownership Percentage	5.00%