XML 82 R68.htm IDEA: XBRL DOCUMENT
v3.22.4

Schedule II-Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Beginning Balance | $ 3,051 | $ 3,037 | $ 4,059
Additions | 3,525 | 14 |
Deductions |  |  | (1,022)
Ending Balance | 6,576 | 3,051 | 3,037
Allowance for Doubtful Accounts [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Beginning Balance | 564 | 564 | 564
Ending Balance | 564 | 564 | 564
Valuation Allowance for Deferred Tax Assets [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Beginning Balance | 2,487 | 2,473 | 3,495
Additions | 3,525 | 14 |
Deductions |  |  | (1,022)
Ending Balance | $ 6,012 | $ 2,487 | $ 2,473

X
- Definition Valuation allowances and reserves additions. + References No definition available. + Details
Name: | gldd_ValuationAllowancesAndReservesAdditions
Namespace Prefix: | gldd_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | srt_ValuationAndQualifyingAccountsDisclosureLineItems
Namespace Prefix: | srt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column B)) -URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column E)) -URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
Name: | us-gaap_ValuationAllowancesAndReservesBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of decrease in valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column D)) -URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
Name: | us-gaap_ValuationAllowancesAndReservesDeductions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForCreditLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |