XML 53 R38.htm IDEA: XBRL DOCUMENT
v3.20.2

LEASES - Additional Information (Details) | Jun. 26, 2020 USD ($) Options | Mar. 23, 2020 USD ($) Options | Sep. 30, 2020 USD ($) | Apr. 30, 2020 USD ($) | Dec. 31, 2019 USD ($)
--- | --- | --- | --- | --- | ---
LEASES |  |  |  |  |
Operating lease, liability | $ 200,000 |  | $ 12,227,000 | $ 4,100,000 |
Operating lease, right-of-use asset | $ 200,000 |  | 11,059,962 |  | $ 455,174
Initial lease term | 10 years | 10 years |  | 71 months |
Number of renewal options | Options | 2 | 2 |  |  |
Renewal term | 5 years | 5 years |  |  |
Fixed lease rent payment | $ 9,800,000 | $ 5,600,000 |  | $ 1,100,000 |
Receivables of reimbursement for out of pocket buildout costs |  |  | $ 1,000,000 |  | $ 0

X
- Definition It represents amount of fixed lease rent payments under the initial term. + References No definition available. + Details
Name: | mrkr_FixedLeaseRentPayment
Namespace Prefix: | mrkr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition It represents number of renewal options. + References No definition available. + Details
Name: | mrkr_NumberOfRenewalOptions
Namespace Prefix: | mrkr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_LeasesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980 + Details
Name: | us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980 + Details
Name: | us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition Present value of lessee's discounted obligation for lease payments from operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977 + Details
Name: | us-gaap_OperatingLeaseLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of lessee's right to use underlying asset under operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977 + Details
Name: | us-gaap_OperatingLeaseRightOfUseAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after allowance, of receivables classified as other, due within one year or the operating cycle, if longer. + References No definition available. + Details
Name: | us-gaap_OtherReceivablesNetCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant